like I have said before, at least test out a 2.1/beta hybrid
keep the betas arsonist, nurse, spy, recon,
but replace the beta's engineer, gunner, borg and marine with the 2.1 engy gunner, borg, and marine
sure the defence classes would be stronger, but their respective sworn enemies are also stronger
this way you got a good D to O balanace, and most of the classes are useful
best of both worlds