I've had my 3520A for over 15 years now. I love it. I think the 3520C has improved the few things I would change on my A series. That being said the Robust just works better. All the locks require only gently pressure to lock and unlock. Everything seems to work more smoothly. I would opt for the Robust in a heartbeat. However money being the issue it is I don't think you can beat the Powermatic in it's price range. It's kind of like driving a Chevy and a Cadilac. Both will get you there and do what they are supposed to do quite well. One is just a little more comfortable.