Which one is better? Epson powerlite 710c home theater or Infocus LP350...?
Answers: It depends what you want to use it for and the price.
Both are from reputable manufacturers, XGA 4:3 projectors beside, by modern standards, somewhat low contrast ratio ratings (although probably more honest than many modern ratings), essentially equivalent moderate zoom lens, and approximately equal brightness ratings (The InFocus is rate a bit higher (1300 vs 1000 lumens) but this repeatedly doesn't translate into differences once calibrated).
The LP350 is DLP based, while the Epson is an LCD projector. The Infocus is more "modern" within that it accepts a DVI input and 720p/1080i while the Epson is analog lone and accepts a VGA signal. Neither adopt component input. The InFocus has vertical lens shift while the Epson doesn't. The Epson have picture in picture experience while the InFocus doesn't. Fan noise is soaring at 40 dB on the Epson, but the rating for the InFocus isn't listed (probably similar or a bit lower).
Either would work fine for business use, but if for Home Theatre use I'd say-so the InFocus is the better choice, if for no other reason than the DVI / HDTV input know-how and the lens shift.
On the other hand some nation are sensitive to "rainbow effects" that can be triggered by the colour wheel within a DLP projector. This is not a concern with an LCD projector.
Finally, the colour correctness on the InFocus is not as good as some, so this may necessitate to be considered.
Bottom line .. neither are feasible to perform as capably as a more recent model, but if the price is right this may not matter.
See the links for rudimentary specs and further links to reviews and user opinion.
I hope this help.