If you have very high end stats, you do have two things going for you:
1. You're not the average Joe, you'll be more noticeable as a serious player.
2. With big studios especially, they need less of a test of performance (they have plenty of access to machines with ranges of capability) as they do with varieties of hardware. Many kids will sign up for a beta test with their crappy computer, but you will stand out as having unusual hardware that they have less possible testers for.
With public beta tests for companies larger than a few people they really are looking for a large variety of machines for best testing entry. Only with really small studios do they not have the capabilities to figure out minimum recommended hardware, and even then they will have far more people falling on the wayward end than the high speck end (which as I've said, they need to test also.) Also, late beta tests (aka the public betas most people get into) are far less about finding out how well it will run on machines, and much more about testing server loads and tweaking gameplay. Earlier beta and alpha tests care more about how well the game is and tuning the game to get the maximum fun and intuitiveness. They care less about minimum requirements as new code is being added, and they will optimize later.
So all in all, beta tests don't care that much about performance as they do about gameplay, and where performance does count almost all the time a high performance machine is better.
