I had your exact same ring problem w/VZW when I had my 6700 with them. My phone would light up (assuming display was off and it was in standby) and I knew that meant a call or text would be coming in. Then nothing would happen. no missed call, etc.
2 hours later, "Why didn't you answer when I called earlier?" I got to the point where when I was expecting a call and I'd see it light up (it was often on the desk next to me), I'd just call them right back and they always would say that they had just tried to call. (Note I do not have this issue with Sprint [6800, 6850])
Battery life is somewhat poor, but I have a couple suggestions:
1) Change your tower polling back to how it was. I know it "helps" the issue mentioned above, I think it to be more of a placebo and not worth the battery life you will lose keeping it like this.
2) check out this post about using Diamond Tweak/Advanced Config to change the amount of time your data connection stays on. I noticed a very huge battery life increase changing this setting alone.
http://forum.ppcgeeks.com/showthread...358#post860358