I've got the Gem sling bag and its identical to the 200AW.
Therefore it has the extra strap to secure the bag on the move (no slipping around) and this can be tucked away when not being used.
I was looking at the same two bags as you and probably would have preffered the look of the crumpler but the Gem was cheaper (£32 delivered).
As I'm brassick at the moment and needed a camera bag pronto it was a no brainer.
I'm pleased with it though, theres a bit more space to put a few small things in the top bit like sarnies on a day out if you needed to, though in my case more likeley to be spare nappies and baby changing gear :baby:
Hope this helps.