If you have a tach, idle should be set to 3200 and full throttle is listed at 12,200-13,400. I set mine somewhere in the middle after my muffler mod. It rips pretty good with a 12" 91VXL chain. That is my favorite chain, although it will chatter and grab in certain types of wood. It does get better after several sharpenings. The second half of the life of the chain is much more enjoyable than the first.
I have had the same issue of it dying when sometimes when returning to idle after full throttle. I'm assuming I need to tinker with the low side screw some more. Did you ever figure out why yours was doing that?