I've got a Z3 and love it. I was looking at what would be the benefits of adding about $1000 to my budget, but the additional cost wasn't worth the slight increase in features for the projectors that I was looking at. I has a little limited in the I have about 11 feet from the front of the projector to the screen and I wanted around 104" 1.78:1 (HD screen ratio). Some projectors need to be further back than 11 feet to get that picture, others were not HD, some had bad reviews, so on and so forth.
Of course the Z3 is LCD, not DLP, but I saw the infamous rainbow effect with DLP. I have always been able to see imperfections in things related to what I would call "refresh rates" of lights. I can see flickering monitor screens when others can't, and I can even tell when a flourescent light is flickering when others can't. People say that some DLPs are better than others, but to get one that should work for me, I was at around $5000+ which was too much. Not that I think that the Z3 is a "last choice." I think that for the price it is the best thing out there. Good luck.
