Use Glock mags with TTI extensions. The ONLY pcc USPSA national champ uses them, therefore it must run...
It's also what I run and I dont see the point of using anything else. I LOVE MBX mags for 2011s too but I don't see the point of them. Altho if someone wants to donate one to me for T&E I'd gladly try one haha
As for dots, I agree with boomstick. Use it until you feel it's holding you back. people seem to like the 510. I have a 512 on a rifle I never use.. I'm excited for when the HS 507COMP is released