You need to read the definition of "beta test". Being in a beta test is about taking a risk in trade for some reward. In this case mostly getting an early chance to play with something. I've gotten T-Shirts, mugs, a rear-view mirror for my monitor, and a Flashscan for being a beta tester. I've also lost everything on my hard drive more than once and the last hours edits of source code more times than I can remember. Risky is testing an editor, insane is testing disk defraggers and caches. I've done all of that, mostly for a few thousand dollars worth of free software. Sometimes when your contribution is way beyond what's expected you get something really amazing, the FlashScan was like that, more often you just get free software. The best reward for me is when I end up with a product that works better for me because the authors listened to and thought about what I had to say.
But before you become a beta tester for anything, make sure the risk is acceptable. And remember, there's always risk. In this case at the easy end it might be you can't tune for a month and if you're desperate you get to pay overnight shipping both ways for me to put it back to the old firmware, or if it really goes to heck your car might not run for a week or need a new ECM. So that's the risk in beta testing EFILive, and with something like stand alone flashing the risk factor is considerably higher then with a lot of other things.
Now you get to think about the past and what problems you've heard about in previous betas, how they were handled and what you can put up with.
And you'll usually end up signing a non-disclosure so you can't officially talk about it except in the beta section or on the phone with another tester or the author.
So think about what it means before you make the choice.
Ira