Well all are good selections. Here is my 2 cents (take it for what it's worth
1. The VPLVW100 Ruby is a great unit. But at this stage, the most expensive of the bunch and for the most part, outshined by the RS1 (which is also cheaper). I would skip this at this point.
2. The Pearl is my choice in the under $4k range. Decent brightness, good contrast, good colors, very well made, etc... Also pretty rock solid in performance.
3. I thikn the Optoma is decent, although it is a bit overpriced compared to some others in this stage. The outboard processor is nice to have and works well. This is a brighter unit, but much lower contrast and the offset can make installation difficult.
4. The RS1 is just shipping but most reports have made it a real good contender for the money. A bit more than the Pearl, Epson and Panny, but if in your budget worth considering.
5. Panasonic...good unit, but the Smoothscreen kills it for me. I think they should have skipped it.
6. Epson is new so I don't know much about it.
I use the same screen and I can say that any will work well with it. Also, you will see a huge improvement over the AE700 (I had a AE900 and these are all way better.