It's great to come back to these threads.
I have the Crumpler 6 Million Dollar Home, and it works as my "Big" bag. (The other bag that I use these days is the Domke F-6, which is a "little bit smaller".) I tried the Crumpler 5M in the store when I bought my 6M, but it was too long ago for me to remember the size difference.
I have the 6M set up to hold my biggest lens which is the Oly 35-100 f/2 zoom. This lens is slightly bigger than its 135-format counterpart, the Canon 70-200 f/2.8IS, and goes in the bag with its hood reversed and tripod collar on. (Yes, 4/3 lenses are supposed to be smaller... they lied.) The hood has a 12cm (4.75") diameter, so it takes up just over one-third of the bag when it's sitting vertically. The other end of the bag holds my E-1 with the battery grip attached, and the middle holds a two more normal-sized items, such as a
small camera body, flash, or lenses.
I don't carry my camera attached to the lenses, which gives me a little more flexibility in storing things, but the main reason is that there's no way to keep the body on the 35-100 and still close the bag. If I want to keep the camera and body attached, like I did on my recent road trip, I need to use a Lowepro Micro Trekker 200. It holds about the same amount as the Crumpler 6M, but with more room for "Stuff" and with both bodies attached to their favourite lenses.
The 6M is bulky to carry around. There's no real way around that -- it's a big bag that fits a massive amount of stuff, so it needs to be boxy and big. The Crumpler also is heavily padded, with foam all around the outside of the bag, and the movable foam dividers inside. This makes it the same size and shape no matter how much is inside of it. (The weight, unfortunately, does change.

) I've never been surprised by how much I can fit into it -- if anything, from its size, I'd expect it to hold more than it does. But I also think that's typical for camera bags. If you want a heavily padded bag, they're great.
...but if I'm not carrying that one monster lens, then I use my little Domke F6 instead. It's canvas and very lightly padded, and gets easier to carry as I carry less stuff. I'm regularly amazed by what it can comfortably fit -- E-1 with grip, four lenses (with the single exception of the 35-100, every other lens I have can be carried in any combination) or more if I stack them, a flash, and various small odds and ends. If I didn't have the Crumpler already, then I'd be looking at one of Domke's bigger bags.