Seems pretty atrocious performance to me, probably the slowest game I've ever played. The View/Detail distance seems to make a fair difference, so I've set them both to minimum. Bear in mind that actual in-game performance is a lot worse than my benchmark score below, quite often it'll be running in the 20s. The game seems to be massively CPU limited (I'm at 3.24ghz, not what's listed below) as it's always running very close to 100% cpu.
Statistics
Average FPS: 43.56
Duration: 37.15 sec
CPU Usage: 95%
System memory usage: 65%
Video memory usage: 83%
Graphics Settings
Video Mode: 1680 x 1050 (75 Hz)
Texture Quality: High
Render Quality: Highest
View Distance: 1
Detail Distance: 1
Hardware
Microsoft® Windows Vista" Ultimate
Service Pack 1
Video Adapter: NVIDIA GeForce GTX 280
Video Driver version: 185.20
Audio Adapter: Speakers (Creative SB X-Fi)
Intel(R) Core(TM)2 CPU 4300 @ 1.80GHz