So, when do you guys know it's time to stop working on a map and release a beta?
^^ Eek! Beta != Stop Work!
See here is the problem, I'd release a beta earlier on, and wouldn't stop for it. I'd develop along side the beta and when the beta is tested, add user tweaks to the ongoing project and release a new beta. When the pressure of the community and your perfectionist side meet, you'll find it's time.
-y00tz