So my wife and I recently traveled to Saint Lucia for a winter vacation. We actually scheduled a guided photo tour with a photographer there, so I wanted to make sure I could bring both our cameras, and we also just got a GoPro for shooting underwater while SCUBA diving, so that needed to come with. Additionally, I always bring my laptop so I can upload pictures as we go, both for backup purposes and to keep family in the loop as we enjoy the warmth of the Caribbean!
Anyway, I initially ordered the 350AW size of this bag, and while it was nice, it just BARELY didn't fit my Dell laptop with a 13.3" screen (it's advertised as holding a 13" laptop, and they weren't kidding, not a millimeter bigger).
The 450, while a little bigger, fit everything just right.
My list of gear hauled in this bag:
Dell Latitude 3330
Canon SL1 with 18-55 EF-S attached
Canon 70D with 17-55 EF-S attached
Speedlite 430II flash
B&W 77 polarizer
4 hoods for lenses
4 batteries + charger for SL1
3 batteries + charger for 70D
GoPro SuperSuit housing
GoPro housing handle
Miscellaneous cables and flash cards and thumb drives.
The total weight of the pack was 22#. It isn't something I'd want to haul around while hiking but it worked great for getting the gear down there safely on the plane. I brought a small Adorama slinger bag for daily use.
Very secure system, hardish shell, fit great in overhead bins, stored lots of stuff, relatively comfortable to carry (as comfortable as a 22# backpack can be anyway).
Kind of expensive ($180). The bag itself weighs a couple pounds, so heavy for hiking use. The access to the lenses is awkward since it goes through a panel that faces your back.
I would definitely buy it again! It will be my haul gear bag for all future trips, but you need a day bag for walking around.