I don't know about the Zinwells anymore, see my post #1117 above. Most of those ratings are probably based on the older version which were pretty good boxes and one of only a couple brands that have recording timers (I use mine as timer tuners input to a DVD recorder and VCRs).
I don't know about the RCAs. Walmart stuff so seem cheap but folks appear to be OK with them for basic units, but nothing fancy. My mom has a pair and they've held up well. I didn't know about the lack of 16:9 if that's true (on some boxes it's called 'squeezed' or the like), I use it to record 16:9 in 4:3 format (VCR and standard DVD) which my 16:9 TV then converts back to 16:9 in one of it's aspect modes (Full); of course the same is necessary to use one of these boxes to display 16:9 on a widescreen set (the early widescreen TVs didn't have ATSC tuners and hence why these boxes have this mode).
Those are rip-off prices on the Zeniths/Insignias. I think they're taking advantage of the popularity of those boxes even though they weren't the top tier. BTW Artec looks to be a Zenith clone with good design&mfg IMO, I have a pair I use when camping since they can run up to 12 V DC.
I would avoid the Coby, Craig, and other drug store genre boxes. I've heard the Apex 250s are problematic but the rarer 502 is 'supposed' be a good box; could be the older 250s were better.
Check Fry's and see if they still sell the ChannelMaster CM7000, maybe online somewhere too. There was a TRT brand that was supposed to be great but online only from the maker. These and the Apex's have s-video output for better PQ.
Here's a very dated but decent general review from ConsumerReports:
With patience you can find used boxes on the cheap and local on Craigslist. Some folks never used them since they gobbled them up just in case with their $40 gov't coupons. I suspect there's plenty on eBay too but CL means no S&H and probably better deals.
Me, I've found a couple of full HD tuners on CL for ~$20 each with a lot of patience. The stand-alone HD tuners were somewhat rare but the satellite companies added HD tuners into many of their sat boxes. The difficulty is figuring out which sat models didn't require a subscription but there's plenty of boxes out there because the sat part became somewhat obsolete as they added more sat channels and features like sat HD. And these are high-end high-quality boxes that sold for hundreds of dollars in their heyday.