The Sony LCOS set is so dramatically better than any other RPTV set I've seen (I saw it at CEDIA in Indianapolis). BUT, it is projected to cost $10,000 and the only announced model is a 70" set that is 25" deep. Not really suited to most small rooms. Still, I plan to shoehorn it in somewhere when it becomes available (projected Jan. 05).
JVC also showed a LCOS RPTV of about 50" size that was priced, I believe, in the $4,000 range. It had nice colors, but suffered a bit from poor black levels. Still, it is worth looking into.
I like the Sony Grand Wega LCD sets, even if the black levels are less than ideal. Because many movies and tv shows have dark scenes, black level has become the most significant weakness of all of the competing technologies, with the exception of the old CRT tv. But, most CRT sets have there own set of problems (burn-in, convergence, poor detail, etc). That is why I prefer DLP sets in the 50"-60" size. I can live with the occasional rainbow.