Never tried a Turion....HP used to offer the full blown Athlons (not dual core) in their systems. At HP.Com I noticed that everything on the high-end side is Intel (faster hard drives, faster/bigger video, etc )
I honestly dont know. 128mb ATI card seems apt and able, I just wouldnt crank the settings in AH up too high. At least it has its own dedicated video memory, not the shared stuff with the system.
Otherwise, I dont think its a terrible system.