After quite a hunt I have found the Tom Bihn Aeronaut to fit my needs in a travel bag very well and the reviews rave about it.
Does anyone have anything to add?
For the benefit of others - I can't recommend this bag highly enough. I've seen (but not used) the Timbuk2 and considered it when I bought the Aeronaut for my husband. The Aeronaut has more volume and is, IMO, better compartmentalised while being more configurable. He is easily able to travel with a suit, dress shirts, ties (all in an Eagle Creek Garment Bag), jeans, sweater, casual gear, jacket, sox, undies, laptop, camera, chargers, toiletries, 2 x shoes, all in this bag. The real beauty of the bag can only be seen once its packed to full allowable weight because it doesn't look anywhere near full. If airport security decide to only check weights on bags that look full then chances are increased that you will walk straight through.
The Aeronaut, if purchased in the ballistic nylon, is slightly heavier than the Timbuk2 bag (3lb 1oz compared to 2lb 4oz). If weight is the greatest concern then the dyneema nylon Aeronaut is almost the same weight as Timbuk2. From memory, the compartments in the Timbuk2 are fixed. The Aeronaut has more compartments but can also extend into the side compartments if desired.
I liked my husband's Aeronaut so much I bought one for myself. As a test, I loaded it to 23kg and tried it out (not on an airline). I'm 158cm tall with a wrecked back and found it easier to lift the bag than to lift a similar weight in a suitcase. Even loaded way more than I would ever load for flying, it was comfortable when I used the back straps.
I have to admit to being a fan of Tom Bihn bags though. My husband travels with the Aeronaut and a Ristretto as his personal bag (iPad, Kindle, noise-cancelling headphones, etc etc). For travel, I use an Aeronaut and a Co-Pilot as my personal carry-on. Neither bag every looks bulky or anywhere near full even when crammed. On a trip last year I loaded the Co-Pilot with 12kg of stuff and despite carry-on being weighed at checkin and the gate nobody looked twice at the personal bag hanging on my shoulder.
I use a large Cafe Bag as my everyday, use all the time bag. I haven't used any other bag for daily use since I got it. This bag takes a 13" Macbook (inside a Tom Bihn Cache for protection) without looking like there's anything much inside it. It would work well as a personal bag for flying. My man prefers the Ristretto with its padded, protective iPad compartment. I prefer the Cafe bag in which I can put an iPad or Mac as desired but have the full bag for use when I am not carrying those. I use Tom Bihn Cache's all the time with my Mac and another for my iPad - don't need to remove them for airport screening.
The TB bags seem to wear really well. Into my second year of using a Cafe bag every day and there is no sign of any wear. The Co-Pilot works well as an around-town messenger bag and has stood up to some pretty rugged wear when I've been travelling. It's also stood up to some very heavy rain without letting any water in.
I've also purchased a couple of Tom Bihn accessories. The 3-2-1 pouch is great. I can put all my 100ml carry-on liquids in, attach it to my bag, and its able to stay attached when going through security. I like the document pouch too as I feel safer carrying important personal documents when they are clipped inside my bag and can't slip out of anything. For the rest of his accessories, you can buy similar but much cheaper from Eagle Creek or any of the others that make decent organisers - or use ziplock bags.