Actually, I think the trial version of PT will only allow 100 hands. I have Poker Office and I would rate it a solid 10 (on a 1-15 scale).
LiveTracker is included and provides current stats overlay for any table you are playing at the time...with PT, you have to purchase an addon.
Simply layouts and easy to navigate.
Customizable charts and graphs.
(This one I don't know as much about) I have read that the database has a larger capacity and operates more efficiently than PT...but I can not confirm this.
LACK OF DOCUMENTATION. I don't know what PT had, but PO has NOTHING for version 2 and only a simplistic manual for version 1.
When using LiveTracker, I do not have access to player chat. This is the case on PartyPoker
and may be true on other sites.
Personally, I don't think you can go wrong with either PokerTracker or PokerOffice. I would only consider these two to be serious choices as they have a majority market share (with PokerTracker being far more popular) and, therefore, more likely to offer support and future improvements.