Kinda depends on your proportion of backpacking gear to camera gear, and how accessible you want the camera gear to be.
Best for me is a dedicated conventional backpack and individual "belt" pouches for my camera gear. Plenty of protection for the camera gear, and you can stow it wherever it makes the most sense in your pack. Any gear you want accessible while hiking, just hang the pouches from your waist strap or shoulder straps. On location, put them on your belt and no need for a second bag. I've never carried a laptop backpacking, so no help there. In fact, I'm NOT going to carry a laptop till they get down less than a pound and are bullet proof against shock.
I always carry a couple of the pouches in my daypack too, for easy access on day trips. My favorite daytrip pack is the largest Tamrac Adventure pack. Don't remember if it's a 9 or a 10 these days. Its space is divided about half and half between camera gear and personal space, plus it has a laptop slot, but I still want those belt pouches so I can change lenses, cards, filters or batteries without taking off the pack to get at it. Space for personal gear is a big deal for me in any pack. Dedicated camera packs don't have any. The Tamrac Adventure packs have more than any other model or brand. Easy choice for me.