I vowed never to go on a weekend again after the 2007 show.
Fortunately for 2008 PH had the Friday access sorted so i made the trip (and enjoyed it) but not for 2009 it seems...so i'll be staying away unless i can sort access for the media / trade days.
Too busy for my purposes (pointing cameras at cars).
If you go on Saturday or Sunday, i'd advise an early start so you get there for the doors opening. It'll give you a chance to look around before it gets really packed.