Yes, it's important to be honest with yourself.

I can run medium but there is a slight lag I prefer not to deal with (and longer load times) so I run low.

I am fine with low, and have alot of fun but some people keep trying to run High and Ultra who clearly cannot run high and ultra.

The demo has some bugs, no doubt about it, but i'd wait to see the full 15 gig version before worrying on how the 2 gig version worked.