I used to carry anything and everything, and 2 of everything! Even just for day to day recording. I still do if I'm doing something big like a gun shoot.
Lately, I've really slimmed the rig down. I bought a Timbuk2 messenger bag that can hold my recorder (744T), 191 in the zeppelin (with cable), the 191 Matrix box, and my Beyer headphones. I have everything in the bag, ready to go. All I need to do is open the bag, turn the 744 on, pull the mic out, and I'm rolling.
That's all I carry most days. Way more important to me these days to be fast and light vs prepared for anything. Again, on a big shoot (guns, animals, etc) it is a very different story, I load up the truck! What I back pack is not all that different from what you guys have already mentioned.
Oh, and I've finally stopped using Portabrace bags. Got so sick of all the noisy velco and how non ergonomic they have become. I remember my Tascam DAP1 bag was awesome. The bag for the Fostex FR2 is terrible, and the 744 bag is only marginally better.