Here are links to some information about the D50 on this forum
Sony's new $600 recorder PCM-D50
http://taperssection.com/index.php/topic,92069.0.html250 messages, mostly people talking about the published specifications and wondering when someone will buy one
Sony's new $600 recorder PCM-D50 PT II
http://taperssection.com/index.php?topic=95964.075 posts, some from people who have used the D50. No real comparisons to other recorders yet, but some "sounds good to me" comments.
The D50 still costs about $600. The Fostex FR-2LE costs as little as $450 on eBay. The FR-2LE is much larger, so it's not so good for stealth recording, but it has stellar preamps, XLR mic inputs, and 48V phantom power for mics that need it. The 7.2V RC car battery option for the FR-2LE provides 7 to 8 hours of recording time.
Flintstone