Soft Wrap doesn't really make things a lot better for me. I'm having the exact same problem as Jim Leask but I actually noticed it when Soft Wrap was already enabled. When I disabled Soft Wrap it got a lot slower. Either way, with Soft Wrap enabled or disabled, with any wrap disabled/enabled for that matter, it's way too slow to not have to switch over to nano to edit the file - which I don't mind doing but it would be great if I didn't have to.
Adam