I am tentatively filing this as a bug report. Perhaps the community can weigh in. Basically I find the ultimate key unresponsive in combat, specifically the resto ult. It's gotten to the point where I am more inclined to alternate Healing Ward and Harness Magicka, when focused in PvP, than trying to activate that unreliable ult. I typically end up hammeriing the ultimate key, and I can see it flickering on the skill bar, yet nothing happens. This goes on long enough - 2 to 3 seconds - that the attacking NB can do their Incap Strike (CC - but please read on), and subsequent attack rotation, and kill me.
I have looked at my ult level numerous times, and it's been 250+. I use Immovability potions, so an Incap Strike or Fear will not necessarily CC me. A CC could be part of the problem on some occasions, but my perception is that I can spam Healing Ward much more reliably than try to activate that bleeding ult. To be honest, it is the sheer frustration of hammering the ult key and waiting for a response that gets me killed. This has happened so often now that I am convinced there is something special about the ultimate key. It just does not register as fast or as reliably as other abilities. Does anyone else have this problem?