I'm thinking about getting 2 RE audio se-x 12's?

I now own 2 MTX thunder 4500's. They get the job done but i wnat more b. Recently i bought 2 polk audio dxi series 12's. they were no different if not worse than the MTX subs. Do you think its worth getting these. Im on a budget. And i dont do competition, but a subwoofer that can peforme like a compition sub would be great. So what do you think about RE audio?