A new patch arrived today, and it seems to have made it a bit more stable now..
I've also experienced that selecting one of the presets (low/mid/high), turning of bloom and choosing shaders 2.0 helps on the stability (it's also recommended by Funcom)
You should also try to create a new character on the newest server since Openbeta #1 is seriously crowded, even if it says low load..
Have you testet PvP yet?
Looks pretty good, even if it's still a bit slow and buggy...
Up to lvl 13 on the Ranger now, and it looks pretty good, but it's maybe too good on close-combat and not good enough on ranged yet (at least up to that level..
)
Testing a Priest of Mitra now...