I'll start by saying I've used
Poker Tracker for about 3 years now and have been very happy. But, I'm always open to improvements. For myself the key ingredients to the perfect stats software are flexibility, function, real-time usability, coverage of multiple poker sites, ability to track tournaments and ring games, and of course as much detail on my opponents play as possible. So last year I gave Poker Office 2 a six month try-out.

My current set up includes
Poker Tracker running with two add-ons, GameTime +, and I also use Poker Grapher to visually track my earnings. So during actual play I have 2 programs running, and GT+ must be told which table is which. It can get a bit taxing on the CPU but the realtime heads up stats display really helps with decision making. what's missing in the table view with GT is pot odds, hand rank, mucked card info, and the ability to track tournament play live. There is an add on called
Poker Ace HUD which will provide all of these features for an additional $25. Poker tracker supports more sites than any other stats package, in fact
Poker Tracker supports ALL of the US player friendly poker rooms. Poker Tracker has the distinction of being the most used and upgraded stats programs out there, but it doesn't mean it's perfect.
Poker Office 2, the first thing I noticed is that it's all in one super clean package; stats, realtime display,

graphing, opposition stats and real-time play info like pot odds, hand rank, and mucked cards. The next big difference was CPU memory usage during play, Poker Office 2 is much more efficient. They support over 50 poker sites, unfortunately they don't support Absolute Poker or World Poker yet. If you brain and monitors will allow, you can track up to 10 tables at once. The integrated graphing is clean and very flexible. Another big plus for me is the number of sites they cover tournaments for (real-time). I got to tell you Just on looks and effieciency alone I was ready to switch, but I put poker office to the test for 6 months to give me a feel for it's realtime usability. The result TWO THUMBS UP... WAY UP! It was an easy process to convert all my Poker Tracker databases to Poker Office 2. As most software packages do,
Poker Office 2 offers the program free if you sign up with an advertised poker room. These are great offers in my opinion. You deposit $50 bucks and play 200 raked hands and the software is yours, and of course youv'e already double your stack...right.
Overall, the decision between
Poker Tracker vs Poker Office 2 comes down to what sites you play poker at, how much CPU effieciency you need, and how much control you want over your data. Poker Office 2 stands out for 1) All in one software package, 2) Greater CPU efficiency during play, and 3) Realtime stats for tournaments at more poker sites. Poker Tracker stands out for 1) The most in depth and flexible stats program, 2) They support ALL US Player friendly sites, and 3) They have the highest level of technical support.
I am a US player who prefers Absolute Poker therfore I currently use Poker Tracker, however when Poker Office 2 gets their support for my poker rooms up I will be switching back to Poker Office 2.