I do service work and protective relay work on switchgear and other substation controls. I tried numerous bags and settled on a Veto OT-XL about 5 years ago and it works well. The side with pockets holds a half dozen screwdrivers, 1/4, 5/16, and 11/32 nut drivers, 7" Knipex cobras, dikes, linemans, strippers, fuse pullers, socket ratchet and extensions, and a few things I'm forgetting. I keep my Fluke in the open side all the time as well as a label maker, fiber or Cat-5 test set, cordless impact, rails of sockets, can of cable clean, etc. as needed. The OT-XL is heavy when loaded, but I typically park within a hundred feet of the work location (think utility substation where you can drive right up.) I have taken it to a few sites where I've had to walk a quarter mile into a plant and it is manageable but if I did that every day I would get a different bag. I typically carry a laptop, associated cables, and paperwork in a backpack. If I didn't need the laptop I would try the Veto or Klein backpack for tools. I would like a backpack that could carry a 17" laptop, hand tools, and a Fluke - I could carry a canvas bucket or a cheap open plan bag when I needed additional larger items.