I own the Panasonic and must say for a projector in this price range I don't think it can be beat. LCoS, on the other hand is better at delivering black levels than LCD's so that may or may not be a factor as this LG model seems to suffer in that area. Since I have no experience with that LG projector I can't actually say that it is better or worse. I am to understand that the LG uses the Sony iteration of LCos, SXRD and I have read that the projector is extremely bright, in many/most cases too bright so that too is something to consider.
The Panasonic is less expensive as well.