Alright, Gamespot has a good Hardware Performance Guide. The screenshots of the different options are priceless as you can gauge what to drop to medium and what kind of performance you will gain plus how it will affect the IQ.
If you haven't see this yet, it's a must read. Seems like dropping shaders to medium will kill the HDR but ~20 FPS gain. (I haven't tried it yet to see what it looks like, I'm at work but a buddy of mine did and said he gained ~19 - 25 FPS and cannot tell the difference in IQ) Now that would make things more playable to me, I've never been a big fan of HDR anyways. And if I can give up HDR to enable AA I'm all about that.
Looks like the shadows images might be messed up. I think Very High and High were swapped. Either way I had been setting shadows to Med, looks like they only got a few FPS from taking shadows from High to Med. Not really a worth gain now that I see their results.
Anyways, here is the link it's a worthy read: