As long as you get a JVC RS-45 with good convergence (and from the sounds of other peoples experiences, you will), it will be as sharp as many DLP's, even sharper than some of the cheaper DLP's.
I do own a JVC RS-45 right now. In the past I have owned the Mitsubishi hd1000u, hc3800, hc4000 (all DLP's). I now own a Viewsonic Pro8200 DLP. So I have owned 4 DLP's. I have seen a Benq w6000 briefly and a bunch of other DLP's. I've also owned a Sony vw70 LCOS, Epson 8500ub, Sanyo z5, and a Sanyo z4000. I know I am forgetting one or two, but those are the main ones.
Out of that entire list, I would only rate (2) projectors a tiny bit sharper over the JVC RS-45, that would be the Mits hc4000 (barely barely barely) and the Benq w6000 (barely), and they are only a tad sharper at best. The JVC is so sharp that these other two projectors will have very little advantage even in HTPC sharpness over the JVC, if even any.
The JVC is ultra-sharp.
See my post here:http://www.avsforum.com/avs-vb/showt...8#post21387038
Stand back about 2-4 feet from your monitor when looking at the above image, and that should be about how text will appear on HTPC on the JVC. Even with the above post, I couldn't capture its sharpness 100% perfectly due to my camera's limitations, but it is unbelievably sharp for an LCOS unit.DLP vs. LCOS
It just depends what you are watching to what will be favored. DLP's are still a bit better in some games because of smoother panning and less lag, but overall the JVC is a good gaming machine (lamps are expensive though), but I still recommend a cheap DLP for gaming and the JVC for everything else. Sometimes bright scenes look better on the JVC even over a DLP, it depends on the lighting though. For poorer sources playing bright movies (think Action movies on Netflix), the DLP will usually look better, other than that the JVC RS-45 wins.
As far as black levels on these newer DLP's, they are not that great. The LS-5 and Planar 8150 and Infocus sp8602 are the only three DLP's I know of in this price range right now with decent black levels. They will not touch the JVC's black levels though.
You can't go wrong with the JVC RS-45 really, but owning 2 projectors isn't a bad idea either since cheap DLP's tend to have cheap lamps and you won't feel guilty for leaving it on all the time.
The JVC RS-45 has at least 10x the native contrast of even the high-end DLP's Native, that doesn't equate to 10x the advantage, but it is significant none-the-less. When you watch a movie like Star Wars or Harry Potter on the JVC, it is a breath-taking experience, it's not like a small improvement, it's huge even over the Epson LCD's.