I'm currently looking at the Kata 3N1-10. I'm on the hunt for a comfortable, flexible bag which will carry a relatively small amount of gear and be accessible quickly, without having to take it off (like a backpack).
The Kata looks like it can be backpack if you want it to be or a left/right shoulder slingbag if you prefer. I need to be able to carry my stuff all day without it becoming painful, but I also want to be able to access my camera quickly if I need to, so this sounds right up my street.
I'm planning on carrying a D90, 18-200mm, 35mm, 50mm and 11-16mm, as well as a few other small bits and bobs. You can also buy a separate tripod holder attachment for around £12 which allows you to attach a decent sized tripod to the back of the bag.
At the moment the Kata is top of my list.
I currently own a Lowepro Slingshot 100AW because I wanted a decent sized bag that I could easily access whilst on the move, without having to take the bag off my back. The Slingshot is perfect in size for all of my gear, but I've found, especially with a tripod hanging off the back, that it starts to become quite uncomfortable carrying all your gear on one shoulder and not being able to switch to the other shoulder. 6 or 7 hours walking around and I'm cursing my decision to buy it.
So now I'm looking at the Kata. Most reviews seem good so I'm going to try and find a local stockist so I can actually try it.
With your big 70-200 the 3N1-20 might be a better bet, but this is quite large in comparison and far too big for my needs.