Like I said, everyone's different. The way I carry camera kit doesn't suit the compartmentalised nature of the f-stop bags and having had a good look at the f-stop packs on the web following this and previous threads then they don't look to have the features and layout I like.
Personally I prefer to have a big empty space which I can then fill as appropriate.
Crap weather and danger of damage? Stick camera in Lowe Pro case, lenses in pouches and chuck in drysack within the pack.
Less extreme conditions? Wrap it in a fleece (if that) and chuck it on the top of the rest of the kit.
Thinking I want to shoot on the move? Then I'll prob take a smaller pack and attach the Lowe Pro case to the outside for ease of access - spare lens in a lens pouch attached to a waist belt or wherever.
Want the camera out? - "Get the camera from the top of my bag" to whoever I'm with, swing it around waist or take it off.
Camping/Bivvying? Carry it all in in a normal mtn pack and then use the Lowe Pro case as a wandering about camp camera handbag.
Not taking the camera at all? Then I've not spent loads on a pack I'm not using.
Want a bigger/smaller bag? Money saved. The protection is the Lowe Pro type small case, the bag is just the carrying system - I'm not paying for the F-Stop system each time.
Imho to make it worth buying an F-Stop then you have to use it as it's intended - ie with the ICU. If you don't like this or prefer a more versatile way of working then you're paying a lot extra and not using it's USP. I still think it's an expensive way of buying a not particularly brilliant daysack and then limiting what you can do with it.
Rather than argue back and forth that the F-Stop is a good mtn pack I'd prefer to hear why people prefer the F-Stop "system" as I just don't see the point.