I think they do play a bit differently for "advertising" purposes, so they'll get more action in their regular games, but not very often. And certainly not as often as the edited tv shows would make it seem.
The other thing to remember is that High Stakes Poker has a VERY action orientated blind structure. With antes in addition to the blinds, it makes it much more desirable to play looser and go after the blind money. So much of the change in their game on HSP in particular is just an adjustment to the game format, rather than just mixing it up to throw off opponents.