I too have been having framerate issues in very specific places, of course, this could all have to do with servers/zone popularity, ect. In some places I get 60+ (on maximum settings) all of the time, others I drop to under 15 with an average of 28-35.
When lowering settings I notice a 5 frame increase, which is of course not worth rough edges and less beautiful vistas.
OS: Windows 7
CPU: AMD FX-8150
GPU: GTX 670
Drivers: 301.42 (I upgraded to the newest, but noticed a increase of lag, and then rolled back)
RAM: DDR3 8gb
Hopefully I’ll be able to play smooth in every zone soon.