Um, you posted this in the wrong forum Anyway.. here's my reply.
If the camera gear bag isn't designed for a notebook, I would most definitely suggest against trying to slot one in, unless your notebook happens to have a very thick sleeve. Notebooks need to be protected by padding.
I happened to have a bag requirement similar to yours a month or two ago. The flipside 400 never came into my mind because it wasn't supposed to carry a notebook (a 13" Macbook unibody for me). It was between the Vertex 100 AW, 200 AW or Think Tank Photo Streetwalker Hard-Drive. I chose the latter. Why?
Firstly, I'm not an adventure photographer, nor a very frequent traveler since I'm a student. I seldom need the very very thick padding that the vertex series gives. Also, since I have a very small built (1.65m) the lighter the weight of the bag, the better (without compromise over padding, of course). Vertex 200 weighs like 3.6kg, versus the TTP SWHD's 1.7kg - more than twice! Definitely not fun when you have, like you said, 5 lenses 2 bodies and a notebook for on-location photoshoots. I liked the exterior materials of the SWHD better than the vertex, and it was a sleek black compared to an 'ugly' (imo) turqoise. The deal breaker for the vertex series was the fact that the notebook compartment was at the front of the bag, not right behind your back like the SWHD - making the bag very imbalanced if you only had minimal gear but a heavy notebook. I like the fact that the tripod holding straps are detachable (requires some thumb-force so that it's not easily undone), and the waist straps can be placed in the 'think-tank-belt' area, giving the bag a very clean profile so that straps don't get entangled in crowds or with vehicles.
One thing the vertex does better is have thicker padding for the shoulder straps.
Sure, the TT is more expensive, but it seems to be better thought out than the flipside 400. If you really want to go with a lowepro bag, check out the computrekker plus. If you're shooting in developed areas, you might also consider rolling bags.