Hey!
I'm just about to purchase a Thinktank Photo Retrospective 20, but since I have never seen one in person, and that size is always different from actual measurements, got a question. I have a Domke J1, pretty big bag and wanting to downsize my bag to something smaller for when I'm not using all of my gear. Ideally I would like to carry the following, I only have a few pockets on the J1 so I'm not going to need too many but would like to make it as easy to access and keep from items falling out. 
(in main compartment)
Canon 5d mark2 w/grip and RRS l-frame
Canon 70-200 f/2.8
Canon 24-105
Canon 15mm
Canon 580 EXII
(in pockets, if possible)
Thinktank Photo Pixelpocket
Expodisc
Small white balance
Extra battery (2 for 5d)
Lightmeter
Remote
