I'm not sure where you're located, but if you can visit both gyms to try them out, I would recommend that. I obviously have my biases but I wouldn't dissuade you from one 10th Planet gym to another. It's really a question of personal preference.
As for reviews: Einstein's one of Eddie's right hand men and first black belts. He knows the system better than a lot of people out there. Our classes are smaller so you get more attention, especially if you're a beginner. And for some reason we have a really young crowd, lol. So you'd fit right in with the other 16-18 year olds.
Try both gyms out and see for yourself! But do email Einstein, haha