It's really funny that nearly nobody can really give a straight answer on the SEO PowerSuite... I've been using the Rank Tracker for 6 months now. My current opinion on the tool is:
- Rank Tracker alone costs you 50$ per year, this is a very low price compared to the 99$ per month that you pay at MOZ
- Rank Tracker performs all the checks with the IP of your company, it will happen that you will need to enter Captchas when using Google afterwards in the browser. This is a bit annoying. I tried to slow it down, didn't work, it only made the check time even slower.
- Rank Tracker is a bit weird to use, it looks like an out-of-date Windows application that runs on my Mac. I love the look and feel of MOZ.
- Rank Tracker also is a bit bulky to use sometimes. Also the competitor analysis could be solved better.
All in all, I'd love to use MOZ, but that is simply too expensive for a little startup firm.
Therefore my advice: If you have enough budget, go with MOZ, you'll be happy, no doubt. If you need a tool to get a bit of insight into your ranks for certain keywords, go with Rank Tracker.