Went over to Dave's place on Saturday and he installed the bag on my 450EXC for me. I mounted it on my old orange fender, so I can just swap the entire fender out with bag attached to it.
Seems like it will work out awesome! need to put my dirt setup back on the bike and go on an adventure :). I was able to fit my north face cats meow large sleeping bag into it with the lower corners still empty for tools and crap.