I went in an A320 sim and the guy who was with me was an F/O for an airline flying A320s. However, he told me it couldn't be logged as he wasn't qualified as an instructor and therefore the flight would not be legal with me as PUT - obviously I couldn't log P1 or P2.
Having said that, if you want to put it in your logbook then I guess that's up to you, so long as you're not going to count it towards jet time.
I also did a flight in a helicopter which I couldn't log as although the guy was an instructor you can't log rotary time in a fixed wing logbook - apparently.
As for getting the best out of it, I found it was a bit like the first time I flew - things were happening around me and I didn't really know what was going on!! We did a circuit at Heathrow, and then an approach and landing at Innsbruck I think. One thing I found was that it takes a while setting things up, so don't waste your hour asking to land at lots of different airports or you'll spend lots of time sitting doing nothing.
I also asked to fly it both with and without the flight director to see how it was. As a PPL flying purely by hand was interesting. And as for auto-throttles - boy do they make it easy! Set a speed, and just point the nose where you want it to go - it keeps the same speed no matter what. Not like my approaches in a PA28