I currently own the Infocus 4805 and have been very happy with it. The time has come to upgrade to a true HD capable device (720p). I am currently looking at either the Optoma HD70 for $1000 or the Mitsubishi 3000U for $1600. Given the price difference and quality, which is the better option?

FYI: I am willing to pay the $1600 over the $1000 only if its really worth it.

I would say go with the Mitsubishi, and buy mine since i'm selling it cheaper than that.....
:)
http://www.avsforum.com/avs-vb/showthread.php?t=796369

The HC3000U is very clearly better, but you can get it for at least a couple hundred less even from the largest online retailer. The HD1000U is also a good choice and only $899 from projector people, but its blacks and contrast aren't as good as the HC3000U, but with simple mods it could easily reach that level or maybe even higher.