I just had a PC about a week ago. It wasn't bad, although I did study quite a bit for it mostly because I'd rather be over prepared than under prepared. It's already been mentioned, but know your memory items, limitations, systems, all the usual stuff. Think of it this way, when you do a LOFT you are usually in for a surprise of some kind, but a PC is very straight forward, V1 cut, single engine ILS, etc. Just study a little bit and stay relaxed.