Most serious photogs will tell you the same thing - next to lens choices, buying a camera bag is one of the hardest things to decide on. There are literally tons of websites recommending the best camera bag to use - try cambags.com for some good pictures of cameras in bags. After my NZ trip where I brought my SR 200 crammed with 2 bodies, 3-4 lenses and a backup and nearly broke my shoulder, I have sworn to become a photo minimalist. Most people simply won't use all that gear when travelling for leisure.
Nowadays, I usually carry a body and extra lens or a small compact digicam like my Fuji F31fd as a daily shooter. For travels, I only carry a single SLR body, 2 lenses max and one compact camera as a backup (used to be my Olympus Stylus Epic, now using the Fuji F31fd) plus a tripod (usually a Manfrotto 3007 Table top tripod, sometimes a Manfrotto 719B). I already have a shoulder bag - a Stealth Reporter which I mainly use in Singapore when I go for events and family occasions, but I wanted a backpack for travelling so I wouldnt have to carry another bag as a daypack plus I wanted a bag that could carry a laptop.
Popular options in Singapore are Lowepro (Compu-trekker, CompuRover, Stealth AW, Compudaypack etc) and Crumpler. As I mentioned earlier, I really like Lowepro, especially their Stealth Reporter line) but most of their traditional camera backpacks make the carrier look like a ninja-turtle i.e. it looks like a person carry a box. As mentioned earlier, I wanted a bag that could function as a daypack also, and the Trekker line from Lowepeo were mostly for dedicated camera carrying use. The designs were really stupid too, in order to access the camera equipment, you have to place the bag on the floor straps down e.g. in dirt etc and open the main flap - too slow to access and ruining a perfectly good shirt maybe.
After spending some time traversing the super-confusing Crumpler website, I finally got the Formal Lounge in Olive. This bag doesnt good enough for someone to want to steal stuff from it, and the main compartment is accessible only from the rear - i.e. facing the person's back. I usually put a bottle of water and into the main compartment in the back, my Manfrotto table tripod in the padded laptop compartment - unfortunately not removable. A 15inch laptop can fit into the laptop area. You could easily slip in a light jacket or even a small flash in there. The bag has external cloth "slots" on the right and left so you could slip a tripod leg into the hook for carrying a tripod; there is no "designated" tripod holder. I hardly carry a large tripod so thats ok.
The main camera compartment is tiny and has 3 padded compartments. You can carry a semi-pro SLR with a mid lens mounted in the middle and smaller stuff like lenses on the left and right. I usually bring my Nikon D70 with 12-24 mounted (or 18-70) plus a 24-120 or a 50mm. If I wanted to carry my 80-400mm, I would have to put this in the main compartment. There is space to carry a blower as well. The camera padding is removable so you can use this bag as a normal laptop backpack.
As for comfort, I carried this bag around Paris for a day with much more gear that I listed above and I survived. A little sore yes - Crumpler makes really hard bags - but it gets the job done. This is not a hiking style bag. The back of the bag has 2 padded areas that gets hot quickly and cannot match the comfort and coolness of my Deuter AirComfort style backpack.
Would I buy this bag again? Probably not. I realize I hardly will bring a laptop AND camera equipment around - the combined weight would be a killer. Mostly for travelling then. But the materials used look like they would last a long time. Hmm.. maybe I could pass this to Harry in lets say - another 10 years :)?