I haven't checked lately, and things may have changed, but at the top of the PokerTracker site is a video banner for PT3 from Stox poker. It gave a quick overview and basic installation instructions for PT3. It was free when I last viewed it.
The basic documentation is pretty good, and constantly being updated. Any and all trackers will take a long time to get used to. They will give you more info than you can imagine tho, and being as poker is a game of imperfect information, the more you have, the better off you are. Though I think Savage Penguin's stance is a bit over the top, I can see how some folks come to depend on the information.
Quick answer to your question is YES, it is worth it.