[puddleglum]

Hi all,
here's the deal. I talked to a guy today about a used E-bike kit. Turns out he has two. One is a front drive Wilderness Energy 500w motor and 36/48v controller. The other is a Crystalyte 400w rear motor with a multispeed cluster and a 36/48v controller. He couldn't tell me the model of the controllers or hubs. I'm wondering which would be the better choice. I've read a rear wheel motor is safer, but never tried either. Is one more reliable than the other? Also, I've read that both companies made brushed and brushless motors. What is the easiest way to tell the difference, and should I stay away from it if it is brushed? The Crystalyte is newer, but was repaired once under warranty he said. Any advise or things I should be looking for would be helpful.
Thanks