TTR 20 or 30 don't not allow camera and body to be carried attached for most lengths. I sold my 30 for just such reason. And with a gripped body, didn't like carrying my D3s in it.
Think Tank Speed Freak is just about the right size if you don't need the 70-200 mounted, and it is just $10 over your price. If you need the 70-200 mounted, you could go with the similar but slightly larger Speed Racer. I have several bags (including several that are similar to ones mentioned in this string: Lowepro AW200 sling, Crumpler 4MDH, and Timbuk2 Snoop), and the Speed Freak is by far my favorite. It is incredibly well made and has a substantial hip strap to take some of the load when you are walking for a while - the hip strap zips away for when you just want a shoulder bag, though. The shoulder strap with this thing is unbelievably thick and comfortable; I read that in reviews before I bought one, and was skeptical as to how much difference the padding of the should strap could make, but after carry it around all day with a EOS-6D, 17-40 f/4L, 24-105 f/4L, 70-200 f/2.8L, and 85 f/1.8, I am a believer.
Anyways, I had never bought a Think Tank product before this because they just seemed so expensive for the features compared to most other brands, but I bit the bullet on this after looking around for a couple months for a bag that had the features I wanted. I'm glad I did; this is the best made, best thought out bag I own and I would encourage you to try to find one to look at in your local camera shop if you can before you buy something else.
I had the lowepro sling 200 but out-grew it with some new lenses. I got a 300 and liked it a lot.
Re: comments about the comfort of a sling, vs backpack... I don't find the sling uncomfortable. The hip straps are well padded and so a lot of the weight is carried down on the hips. No problems on the shoulder plus I suppose it keeps the center of gravity lower, or rather where it's attached. Definitely easy access by 'slinging' it.
A comment on Lowepro customer service: Excellent. I had a zipper go out after quite a few years on the 300. (the 200 still is fine). I live in NorCal so I called Lowepro in Petaluma and asked about zipper repair possibilities. They shipped me a new one in a couple days, no charge. New model - 302, which I also like. Plus: don't forget that hidden 'rain coat' in the bottom !
I just picked up a little Lowepro Event Messenger 100, based partly on my personal experience with the company, but also on the reviews. This one is for an M4/3 rig. Lots of utility there for that.
If it doesnīt have to be a backpack my advise would go toward the Lowepro TL pro 75AW.
I just ordered one because my 6 year old TL 65AW doesnīt hold a 80-200 or 70-200 attached and since itīs my most used lens I wish to have it on the camera the moment it comes out of the bag.
Buy a 11x14cm lens case to go with that and you can take 2 lenses, a flashgun and most of the small parts needed to take pictures while having direct access to your camera.
