If you haven't done so already have a look at this:
http://www.dpreview.com/reviews/q209grouplongzoom/
The ZS3 (TZ7) fares very well but, as you'd expect, is better at some things than others.
http://www.dpreview.com/reviews/Q210...oom/page24.asp
In this group test the TZ8 and TZ10 don't appear to come out quite as well against the competition.
The important thing is getting a camera which suits your actual needs.