I only use my 750 when traveling and so can afford some downtime, and in any case can unbrick it easily enough back to 2.27. Let me know if I can help.
(If others wish to try, feel free to reply too.)
@kennethrc If you can change the thread title removing the AR750 it would be nice, since i want to apply for the Mifi version of v3 :P. You could also made a list in your first post of all the people that want V3 and what device, so @alzhao can see them all easy.
Good suggestion; I’ve made it more general.
I’d love to test out new firmware on the ar750 now that I’ve got a stable configuration to fall back to.
I want to test the new firmware!
I would like to test new firmware for m300n v1 Thanks.
Surely no need to “sign-up”. Betas are posted here (when available):
Think of private and public beta. The public beta is when it’s nearly done. We want to test the bleeding edge one 
Okay guys. We will put bleeding edge firmware for testing this month.
Thanks @alzhao, and I should have been more clear. Yeah, here I’m looking for the equivalent of “nightly builds”, or at least some periodic bleeding-edge builds which at least boot on the device 
We don’t have nightly builds but we will publish testing firmware quite often for testing.