Ask 5 people, get 5 opinions. I am going to have a demo of them next week as I have made the same choices (pioneer and panny). Nothing like seeing the beasts side by side. I suppose there is always some subjectivity in the matter.
Well as PVR said everyone has their own opinion, but most people including the experts tend to agree that the Panasonic 4 and 5 series are excellent. I own a TH-42PWD4 and all I can say is "excellent". You won't go far wrong with either a 4 or 5 series, just superb!!
On what site.. homecinemachoice. Well homecinema and what hifi and those sorts aren´t really that deep reviews, they seem to have their hands full and review alot, so they don´t really check out the gear that much technically or compare against other stuff. But it´s always nice to see a good review.
The dealer here is gonna get a 43" Pio next week, can´t wait to check it out