I always found the personnel at Green Mountain Family Shooting Center very rude and unprofessional. I tried to shoot there a few times to support their business, but they always managed to change my mind when I got there. In that respecy they weren't much different from when they were K2. They also seemed to be trying to rip off The Family Shooting Center at Cherry Creek, and would not admit there was another range named The Family Shootng Center in Denver claiming they were the only one.
As far as GMG, I went a lot before they moved, not so much anymore. Their prices on used stuff are still pretty reasonable, but to me they're not as friendly as they used to be.