OK, folks, here's my report:
Special ordered (2) DTT901 boxes from Stockton Circuit City on June 28th. Total cost including tax was 42.88. Picked up boxes on July 4th. Here is label info:
Build date both boxes - May 2008
Bar Code both boxes - 7 19192 17340 8
I live on a 50-foot motoryacht with flybridge and radar arch, berthed in a yacht harbor in Stockton. Although I am on an outside side tie, there are many metal sheds for smaller boats in the harbor. Antenna is a Glomex omni-directional mounted on radar arch and connected by coax to amplifier in engine room. Output of amplifier goes to 2 -way splitter, one leg to Sony 19" flat screen in salon and the other to 13" Magnavox in stateroom. The leg to Sony also has a 2-way splitter installed so that one leg goes to Sony and the other to Panasonic VCR. Magnavox, Sony, and Panasonic are all about 7 - 8 years old, but in very good condition. Installed one DTT901 on input to Magnavox and one on input to Sony. Panasonic still hooked directly to Glomex antenna.
Performance - Excellent all the way around. No discernible video or audio problems as previously reported by others. I get all the channels I previously received, but now there is no snow or ghosts on any. In addition I am receiving about ten channels more than I did before. PQ is near perfect. Pass-through works exactly as designed, and I can still get the channels that have not yet switched to digital. I addition, my VCR works exactly as it did before, so I am able to watch one channel with digital while recording another on analog. Also, programming the Zenith remote to power on/off the two TV sets was simple and trouble free. I used RF cable to connect both boxes to TVs. I tried the Audio/Video cable, but the PQ was slightly better with the RF cable, possibly due to overdriving the signal with the antenna amplifier.
Summary - I originally was going to purchase the Microprose MTI-500PT boxes, but switched to Zenith when NTIA delayed approval of the Microprose. I am completely satisfied with Circuit City and their special order procedure, the Zenith boxes have been easy to install, and their performance has been excellent in all respects. I highly recommend them.