I recently bought a Qumi 2 off Amazon used for $414. It was direct from amazon, and I am amazed at this little thing. Checking the hours on it, I was surprised to find it only had 39 hours.
I didn't get a high gain screen, just a generic matte screen, 92", and it looks good in our living room. At some point I'll upgrade to a high gain, but for now, this is just about right for our home.
It has the warm up focus issue, which is a non-issue for me. We built an itx bookshelf PC to feed it yummy source material. We're using an AMD A8-3780K APU that has an onboard Radeon HD 6550HD GPU. It works well with anything I can throw at it. Games, blu-rays, etc. etc.
The only 2 issues I have is that the Qumi is not HDCP compliant, so to play bluray discs or other protected content, I have to crack the DRM...so additional software is needed. The second item is mounting it. Our living room is a logistics nightmare for a projector...which I didn't realize until we actually got the screen and projector.
With it all set up, connected to our Wii and HTPC, this thing is amazing. We use it 10-16 hours a day. It'll be less in the summer, but we'll have some movie nights outside as well as some wii tournaments.
No more TVs...