I just posted a longish review of the ST-S7 on the Yahoo FMTuner Group. Maybe TIC will pick it up but they no longer offer an email for contributions. Posted a couple of photos too. Although light, the construction quality is more than adequate and a cut above Sony's JX series, et al. For example, the top and bottom covers had vibration attenuating materials on them.
I did a comparison of the Sony vs. my Philips 673. The Philips definitely had superior sound but with the Sony (and great atmospherics tonight) I was able to listen to KBOQ for the first time, the classical station in Carmel, 50 miles away on the other side of Loma Prieta. With the Philips, I couldn't reject the adjacent cowboy station at 95.3. The cowboy station's broadcast antenna is on Loma Prieta on the line of sight with Carmel. I had to use narrow bandwidth, no muting, and pre-set the frequency then twist the antenna until I heard the Brandenburg Concertos rise above the twanging.
The McIntosh MX113 also sounded better even needing an alignment and recap. However, the Sony didn't sound bad at all. I'd rate it in sound quality above the Sanyo Plus T35 and the Denon TU660 I had and sold.
The guy on eBay is ambitious. There has been NO information on this tuner that I could find. Sony ST-5000FW have been selling not much above that price and is a well known and understood device. If sound quality is most important, I'd get a ST-5000FW first even for more bucks. The S7 is very convenient and has good adjacent and alternate channel performance. Its cute too.
Now that I've done the homework for us all, people can reasonably pay more than I did for the S7 since the risk is much less assuming you trust my report). I'd like to read a comparison of the S7 and other Sony digitals like the 730ES or 707.
All in all, a decent tunerwith nice style, pleasant if not exemplary sound quality, and lots of convenience. Glad I spent my $55 for it - that's a bargain.