Also keep in mind that testing isn't all fun and games. Or, as I wrote on the FH2 forums on the Bf2 1.50 patch:

...way too many people don't get what "beta" means. "Beta" means "OK, the devs need a hand getting this finished as they don't have enough testers themselves or want to speed up the testing process, so let's download this and search it for bugs and glitches and give constructive feedback". It does not mean "woot we r get 2 play teh game early yay us ".

Testing is fun. It does allow you to play with maps, vehicles, weapons and new game mechanics before everyone else. It also is probably the best way to influence the direction of the mod, as testers have a significant influence on the developers. But keep in mind that it's not only fun and games. It has its tedious moments. So if you sign up as a tester, keep in mind that while there is lots of fun and learning and opportunity involved, you'll also be called to test when the test session is little more than "hop on this local server and cap all the CPs on this map to make sure it works".