I would run some tests on your HD CRT before I go all in on a PVM (if you have a Dreamcast, the easiest solution is the 240p Test Suite). I would be inclined to say that a low/no-lag HD CRT would be a better device to own than a PVM. I have an HD projection TV that has ~37ms of lag on HDMI and composite inputs but no lag on component input. I will hold on to that TV like grim death.
I had considered getting a PVM myself, but I think instead I'm just going to get a better arcade cabinet. The cabinet I have now has a low-res monitor, and while I was in Tokyo a couple of years back (partially to buy a Framemeister, natch) I saw some Taito cabinets with med-res monitors that looked amazing.