I wish I had more to offer. While I don't see any impact on my framerate when panning in an area with a low number of PCs, I have always seen an impact on my framerate when panning my camera in a populated area, such as most Aetherite locations. That said, my system is still capable of maintaining over 30 FPS even in dense crowds. One option (which is only available to Windows users, for some reason) that I've used is to turn the number of players displayed in my area down from Maximum to Minimum. The setting is in System Configuration > Other Settings > Character and Object Quantity.