I've still been using 11.3 with City of Heroes since 11.4, 11.5 and 11.6 caused crashes after 15-20 minutes.
I'm not sure where we can start testing, but I do have list of unstable drivers with CoH.
Unstable 10.10 and 10.11 with 5770
Stable with 10.9 and 11.3 with 5770
Stable with 10.6 with 5750
Stable with 11.2 and 11.3 with 6870
Any progress on this? I am really getting frustrated with the random lockups in the middle of a task force - only to get booted from the team, and loosing hours of effort!