I'm taking my MEI Voyageur on it's first work trip next week - it holds quite a bit, and it has a real hip belt, unlike than the Executive Overnighter.

I only need casual clothing for work trips, so I like the single large compartment, and because it's much more rectangular than most backpacks it holds more for it's size.

The only other travel pack I know of with a decent hip belt is the Osprey Farpoint 40, but it definately looks less business than the MEI Voyageur.