I've auditioned the Panasonic and the Mitsubishi, and found them overpriced (by a long margin) and disappointing in contrast ratio and black level. Pity.
I also checked out the JVC D'Ahlia (D-ILA RPTV). It looked absolutely awful in the store where I saw it (several times worse than the Mitsubishi DLP), but I'm told that they can be made to look okay. It's also quite expensively priced, though. The problem with the D'Ahlia is that JVC has very few dealers in California (my state). Two, actually. None near me, and none which are HT shops that would bother to have the set calibrated. Very sad.
By the way, RPTV units are discussed more often on the HDTV Hardware part of this forum, and you should be able to find more opinions over there.