The answer is: it depends.
The Infocus is brighter than the Sony. If you're putting the projector into a room with ambient light and/or light-colored walls and ceiling, the Infocus will do a better job.
The Infocus is a single-chip DLP, the Sony is a 3-chip SRXD (LCoS). If you're sensitive to the DLP "rainbow" effect, get the Sony. Note that the current-generation 1-chip DLPs have minimized the rainbow effect to the point where only a few hyper-sensitive people (such as me!) see them anymore.
If you're planning on ceiling-mounting the projector, the Sony has vertical lens shift, the Infocus does not. Vertical lens shift allows you to tuck the projector closer to a tall ceiling.
If you're planning on shelf-mounting, the Infocus is smaller, lighter, and has a longer throw distance.
The Sony is quieter than the Infocus. If you're mounting the projector directly over your head, this will be important.
DLP produces a very "sharp" picture, with well-defined edges and lots of apparent resolution. SRXD's picture is a bit softer, more "film-like." If you are planning on mostly movies, the Sony may be a better choice. If you watch a lot of sports and regular TV shows, the DLP may be a better choice.
