I don't know why, but the beta client was far more stable than the release client has been for me. I have a gaming laptop running Win 8.1 x64 with an nvidia 750 graphics card.
During beta I was amazed at how stable the game client was and bought the game in part because it seemed so polished. The only real problems seemed to be server-side stuff like broken quests.
Now the release client crashes on me almost constantly. Any single hour of play time includes from 1-5 crashes regardless of what I'm doing. Running around, zoning, chatting with an NPC, harvesting, whatever...
I've updated and then downgraded my video drivers from stable to beta to stable again, but it hasn't helped.
For comparison, Skyrim plays rock solid, as do other games I play.
What can I do to fix this?
I'm also having this very frustrating problem where I'll be in the middle of a fight and suddenly I can't do anything but walk around slowly and drink potions. Attacking doesn't work, abilities don't work, ultimates don't work. Clicking the mouse buttons repeatedly does nothing at all.
The only thing that fixes it is dying or a reloadui, which takes so long it's almost certain death anyway. But on the few times I've lived through the reload, suddenly it's fine again.