I have the
CM7000,
DTV-Pal Plus, and
Tivax STB-T8, and can contrast their features so you can make a decision about whether you want to try the Tivax STB-T8 or duplicate one of your other boxes.
Tuner Performance
Overall, I would say that the Tivax STB-T8 rates a "very good" rating on sensitivity, roughly on a par with most other top performing boxes, but the CM7000 does seem to have somewhat better sensitivity for very marginal stations. For example, on one of my weaker stations, It took a little fiddling to get the Tivax STB-T8 to lock in with a solid 100% signal, but this isn’t too bad considering that, on the same antenna and station, I have never seen my DTV Pal Plus report a perfect 100% signal lock for more than a few seconds. This may in part be due to differences in the calibration of the signal quality readout on each box, because, in practical terms, I don’t find the difference in performance to be noticeable unless the signal is right on the ragged edge. For example, as long as the signal quality is hovering in the 80% to 95% range, the DTV Pal or Tivax STB-T8 will display perfectly clean video for hours on end. Under the same conditions, the CM7000 tends to report 100% quality, but gets choppy on video if it’s signal quality drops even a slight amount from that level.
GUI and Screen Fonts
The Tivax STB-T8 has reasonably sized fonts that have good readability for all on-screen menus, and the CC text fonts can also be changed to a larger size (it does not suffer from the ultra tiny fonts that the CM7000 uses). Several users of the STB-T8 have commented that they didn’t like the dark blue color scheme, so I would have to give the nod for overall esthetics and readability to the DTV Pal Plus, but the Tivax gets high marks for simplicity and usability.
Remote
The Tivax STB-T8 has the simplest, best laid out remote of the three, but it gets a slight downcheck for not complying with the NTIA CECB requirement that the box work with existing universal remotes. Tivax claims they support universal remotes, but when you look closer, you see that they are only talking about an
IR learning type that can make up for Tivax’s lack of standard codes by learning all the specialized proprietary Tivax codes directly from the Tivax remote. The CM7000 is a bit better in this regard, because you can at least turn the box on and off and control channel selection and volume using standard Pioneer Cable Box codes (even though you will still need an IR learning remote to custom learn some of the other keys, this does technically meet the minimal NTIA requirements). The DTV Pal was the best of the three by far for working right out of the box with my existing universal remote. Once I set my RCA 850 universal remote to use the recommended echostar satellite box codes, I found that even such specialized keys as guide, info, menu, etc. were all supported on the DTV Pal Plus using the universal remote with no custom key programming required.
edit: I should also mention that the Tivax STB-T8 remote is more limited in range and works over a smaller angle vs. the CM7000 and DTV Pal Plus. The T8 remote is perfectly usable, but I would say slightly below average for an IR remote in both range and response angle, where both the CM7000 and DTV Pal Plus remotes are above average, and will work with the remote pointed just about anywhere in the room.Electronic Program Guide
All three boxes have EPG support with channel guides that can look forward at least several hours, but the Tivax STB-T8 EPG is the most basic of the three. On the Tivax, when you bring up the EPG, you get only a simple now/next banner display with two events visible at a time; with full details available only for the one of the two that is selected. You then have to scroll ahead through the guide using the left right buttons on the remote. All three of these CECB boxes limit the length of the detailed program description text, but the Tivax STB-T8 was the worst offender here, chopping off the detailed program description text after only four lines. The CM7000 displays EPG title info several hours ahead on a single screen, which is an improvement over the limited info shown by the Tivax, but the CM7000 gets downchecked badly in my book due to it’s micro sized fonts. As several folks have already noted, when it comes to the Electronic Program Guide feature, the DTV Pal Plus is the clear winner. Not only is the information displayed with large fonts in a nice clean format, but the DTV Pal Plus can display guide info several days in advance if your stations broadcast data this far ahead. Even if only 12 hours of info is available, the Pal Plus also has extra memory to cache the guide info for the channels you are not currently viewing, so you can display a full cable-box style EPG for all channels at the same time, without having to tune to each channel.
Video Quality
As far as video quality goes, my Tivax STB-T8 is slightly sharper than either my CM7000 or DTV Pal Plus. None of the CECB boxes I have seen are as close to DVD quality as I would like when it comes to sharpness, but the STB-T8 came the closest. The STB-T8 is also the only box that allows full zoom settings to work with 480i SD video content. This may be important to you if you want to center-crop video that was intentionally letterboxed inside the 704x480 window. CM7000 and Pal Plus use the same chip set, and do not seem to support zoom settings for 480i. On the down side, because 480i zooming IS supported on the STB-T8, but auto-aspect setting is NOT supported, you end up spending a lot of time resetting the zoom ratio when switching channels. (this is avoided on the Pal and CM7000 because 480i always displays un-zoomed regardless of how you have the zoom setting configured for 16:9 HD content)
Construction Quality
All three boxes are reasonably well made, but I think that to be fair, I would have to give the nod to the STB-T8 as being the most solidly constructed. There have been several complaints in this forum about the buttons on the CM7000 front panel being flaky and breaking (the DTV Pal Plus dodges this by not offering front panel controls of any sort). The Tivax STB-T8 does offer front panel channel select and power buttons, but they seem to be pretty solid by comparison to the CM7000, and I have had zero problems with them. Some have commented that the DTV Pal Plus plastic case does not have ventilation slots, and consequently runs a little hot. I don't see this as an issue, because I have simply flipped my DTV Pal Plus up on edge (90 degrees rotated with the antenna input on the bottom). This position promotes much better air flow, and it runs fine and barely even gets warm.
Other Features
The Tivax STB-T8 is the only one of the three to support a smart antenna, and an RS232 port for remote control and software upgrades (though none are available at this time). The Tivax also has a very wide range ‘universal’ input power spec (from 110 all the way up to 220 volts!) so it should be safe to run it on a low cost 12VDC-to-120AC inverter. I have run my STB-T8 on such an inverter several times, and it seems to work perfectly, with no noise in the video, and no noticeable extra heat whatsoever (Power draw on the 12V side is only about 1 Amp). This combination makes the STB-T8 a possible choice vs. a battery or DC operated DTV tuner in a mobile home or RV application.
The DTV Pal Plus is the only one with an extended program guide and multi-channel programmable timer support (for recording multiple programs on different channels at different times).
The CM7000 is the only one of the three boxes with S-Video output capability. S-Video does offer a slight improvement over composite on the CM7000 but, as I noted above, I have found that the Tivax STB-T8 looks slightly sharper than my CM7000 (even though the STB-T8 is limited to composite video).
Edit: I wanted to follow up by answering a simple question that some might want to ask, "Now that you have seen all three boxes, which one would you pick?" My answer is that I am very happy I picked all three of them, and would not trade any one of them for a second copy of one of the others. All three of these boxes are good solid performers, and I haven't really found a major issue with any of them, so if I had to buy another box tomorrow for some reason, all three boxes would be in the running depending on the features that I needed. On my large screen set with S-Video (where the small guide fonts are not an issue), the CM7000 is a real solid performer especially with weak signals. I am using the Tivax STB-T8 with my DVR, where it gives very sharp clear recordings and the zoom ratios it provides let me get perfectly cropped recordings without any garbage lines or other artifacts in the video (and if I want to try a smart antenna later, the T8 will support that). The DTV Pal Plus has the best Electronic Program Guide by far, and it offers sophisticated features like EPG search capabilities and recording timer support that I really like. In a perfect world, a single box would have ALL these features, but if such a box exists I haven't found it (and if it did exist it would probably cost more than I would want to pay), so overall I am happy with the mix of features that these three boxes provide. 


-Delphin