It's good for a little while, but it soon becomes very annoying when it starts harassing you with accusations of being used commercially, even if it's not. I've used it personally in a few different environments, on different computers, all non-commercial, but each time it claims that it's being used commercially.
It helps me with my own productivity enough to where I may have considered purchasing a license just to stop the annoyances, but $30 is a bit steep for that. For what it does, $5 or $10 would be reasonable. Then again, the hostility factor of the messages and their website regarding free vs. commercial would make me still want to look elsewhere.
I think it's a bit deceptive to offer it for free and then have it stop being functional at the slightest sign of being used "commercially." It just seems greedy to me. In my opinion, a donation model would be a better one for PE rather than this one which just repels people.
License: Free Details...