I took my camera on vacation, and my bag was a poor choice. I took my retro10 to carry my dslr with grip, and single lens. I used the raincover, and hated it. (see edit) The bag was much larger than I needed. After the first day and 15 miles of walking, I left the bag in the hotel.
When I came home, I bought a Billingham Hadley Digital to carry my d300s with 18-200 mounted. The camera fits easily in this bag; it is a shooter's bag. My camera is always protected from rain. I can pull the camera out quickly and shoot. I have added a pad on the strap.
Surprise! I can carry that rig with the grip attached! It is a tight fit.
Regrets? I would like a little bit larger bag.
My Domke F3X is exceptional. It carries more gear, very well. I slip a garbage bag into it in case the weather is really nasty. I should have taken that bag to Cape Cod.
I have another, more unusual bag. I sometimes use a Maxpedition Colossus. It allows me to carry other gear as well. However, it is not so comfortable to carry. It looks nasty.
edit: Just found the video on the Think Tank site showing how to use the raincover. It explains it well. However, before saw the video, on Cape Cod with an Atlantic storm approaching, and putting the cover on without help, I didn't like it at all! Now understanding this feature, Perhaps a Retro20 is in the books...Before seeing the video, putting the raincover on was like assembling a Thule rack....or IKEA furniture