The difference between a travel pack and a backpacking pack is largely one of details. Mainly, a travel pack should be designed so that the straps can be completely tucked away, as many airlines dont like to check bags with loose straps. Some have handy pockets for wallets or passports, and many also have zip-off bags attached to the back that can be used as daypacks. (I strongly advocate their use, along with displaying a large neon sign that says Im a tourist. Rob me!")
Interestingly, although the Deuter Quantum 70+10 ($209; www.deuterusa.com) is billed as a travel pack, it really is a pretty straightforward backpack. To me, thats a good thing. For instance, it has an excellent suspension that is not compromised by a stowaway feature. Instead, a zip-out cover basically puts the pack in its own duffel, an approach Ive always advocated. It does have one of the previously mentioned removable daypacks, but you can leave that at home.
So I wouldnt have any qualms about taking the Deuter on the Superior Trail next year. Its a solid pack that will manage 40 pounds or more fairly easily.
As an aside, a pack I regard as a typical travel pack is Eagle Creeks Grand Voyage 90L ($220; www.eaglecreek.com). Its a big pack, 5,600 cubic inches, with stowaway straps, boarding pass pocket, day pack, and other travel-friendly features. Id take it to Italy or Indonesia, but I wouldnt take it backpacking. The suspension just isnt designed for extended hiking with heavy loads. But its a great travel pack.
Check out this years more than 400 must-have gear items, including a comprehensive backpacks section, in the 2006 Buyers Guide.