Kudos for being thorough, HDTV1080P24. 
This may help some people decide whether the box is right for them. I found a few things of note in your review that I'll respond to:
A 7200 RPM HDD isn't necessary for a DVR, because a DVR doesn't need to perform any rapid read/write operations. If anything, a high-speed HDD is worse for DVR applications, as it will use more power, generate more heat, and potentially fail sooner than a drive that spins slower. Especially if you plan to use videobruce's internal HDD strategy, a 5400 RPM HDD would be closer to ideal.
It also probably won't be necessary to support HDD capacities above 2 TB for a while. Even current 1-2 TB drives seem fairly unreliable compared to drives with 500 GB capacity or less. HDD capacity has apparently risen faster than the technology can stably support, as high-capacity drives often have unflattering reviews on sites like Newegg. A 2 TB HDD may be convenient for storing lots of programming, but it will be much worse if it dies and takes all of that programming with it. Since the VRX uses external USB drives, it may be better to consider buying multiple 500 GB drives instead and swapping them as needed.
Regarding your comments on channel scanning, VHF 2-6 can still be used in the United States for DTV, although most stations have moved to UHF or at least VHF 7-13. I'm also not positive, but I'm fairly certain that there is no need to be concerned about cable companies encrypting local QAM channels. Doing that is illegal under FCC regulations. All basic cable packages are required to provide local channels in unencrypted form, but the provider is allowed to encrypt premium content (i.e. cable-exclusive channels).
I will also second your comment that a detailed signal strength meter is highly useful, especially if it will stay on the screen permanently while the user performs antenna adjustments. Having the signal meter disappear after a few seconds makes the adjustment process much more difficult. One feature I found beneficial on the old Zenith DTV converter boxes was that the signal meter would also beep (with faster beeping indicating a stronger signal), which made it easier to adjust the antenna by eliminating the need to also look at the screen to see the results.
Finally, I don't think there's any need for the VRX to add 2:3 pulldown for 1080p24 content, as any 60 Hz HDTV has the ability to telecine material on its own. The only benefit of having the VRX do it natively would be if the user's TV was particularly bad at it, but the technology has existed for so long that it's doubtful one box would do a better or worse job than another.
Native output modes are also discouraged over HDMI connections, because it isn't possible to change resolutions without re-establishing the HDMI link. Since HDMI includes asinine copy protection, the renegotiation often takes a second or more, which makes changing channels on a DVR take even longer than it normally would. There also is theoretically little benefit in having a native output mode, since no HDTV is capable of displaying both 720p and 1080p natively. Each set has either one resolution or the other, and the non-native resolution will have to be converted up or down to match the display's resolution. Since letting the DVR do the conversion eliminates the need to reset the HDMI connection repeatedly, it's generally more popular to do it that way instead of letting the TV up or down-convert the video itself.
This may help some people decide whether the box is right for them. I found a few things of note in your review that I'll respond to:A 7200 RPM HDD isn't necessary for a DVR, because a DVR doesn't need to perform any rapid read/write operations. If anything, a high-speed HDD is worse for DVR applications, as it will use more power, generate more heat, and potentially fail sooner than a drive that spins slower. Especially if you plan to use videobruce's internal HDD strategy, a 5400 RPM HDD would be closer to ideal.
It also probably won't be necessary to support HDD capacities above 2 TB for a while. Even current 1-2 TB drives seem fairly unreliable compared to drives with 500 GB capacity or less. HDD capacity has apparently risen faster than the technology can stably support, as high-capacity drives often have unflattering reviews on sites like Newegg. A 2 TB HDD may be convenient for storing lots of programming, but it will be much worse if it dies and takes all of that programming with it. Since the VRX uses external USB drives, it may be better to consider buying multiple 500 GB drives instead and swapping them as needed.
Regarding your comments on channel scanning, VHF 2-6 can still be used in the United States for DTV, although most stations have moved to UHF or at least VHF 7-13. I'm also not positive, but I'm fairly certain that there is no need to be concerned about cable companies encrypting local QAM channels. Doing that is illegal under FCC regulations. All basic cable packages are required to provide local channels in unencrypted form, but the provider is allowed to encrypt premium content (i.e. cable-exclusive channels).
I will also second your comment that a detailed signal strength meter is highly useful, especially if it will stay on the screen permanently while the user performs antenna adjustments. Having the signal meter disappear after a few seconds makes the adjustment process much more difficult. One feature I found beneficial on the old Zenith DTV converter boxes was that the signal meter would also beep (with faster beeping indicating a stronger signal), which made it easier to adjust the antenna by eliminating the need to also look at the screen to see the results.
Finally, I don't think there's any need for the VRX to add 2:3 pulldown for 1080p24 content, as any 60 Hz HDTV has the ability to telecine material on its own. The only benefit of having the VRX do it natively would be if the user's TV was particularly bad at it, but the technology has existed for so long that it's doubtful one box would do a better or worse job than another.
Native output modes are also discouraged over HDMI connections, because it isn't possible to change resolutions without re-establishing the HDMI link. Since HDMI includes asinine copy protection, the renegotiation often takes a second or more, which makes changing channels on a DVR take even longer than it normally would. There also is theoretically little benefit in having a native output mode, since no HDTV is capable of displaying both 720p and 1080p natively. Each set has either one resolution or the other, and the non-native resolution will have to be converted up or down to match the display's resolution. Since letting the DVR do the conversion eliminates the need to reset the HDMI connection repeatedly, it's generally more popular to do it that way instead of letting the TV up or down-convert the video itself.
and it will record 4 cable channels at once. It requires a CableCard rental of $3.99 a month but the detailed program guide in Windows Media player is completely free. I know people that have a dedicated 3TB internal hard drive in their PC and with a subscription to cable premium channels they are able to record 4 HD movie channels at once on the DVR and playback a previous HD recording at the same time. Also the software appears to have a option to burn the program onto a Blu-ray or DVD but I have not tested that feature to see how well it works. Any PC on the home network can access this 4 tuner QAM PC card. My point is the CableCard feature makes it easier for companies to offer a free Premium program guide. There is no program guide subscriptions at all with the Ceton Infiniti TV product.
