drbobguy--

Coincidentally, I have a North Face Yavapai and an Osprey Porter 46, and I can confirm that if you can do 10 days with a Yavapai, you can easily do a month with the Porter. Also, the Porter's easier to pack and unpack, since it unzips almost all the way so that you can flip it open, rather than having to shove things down into it. I think you'll be happy with it. And while I wouldn't want to hike with it, I found it comfortable enough for walking to and from the station, standing while riding on city buses, etc.

One OT thing, though. I realize YMMV, but do you really never bring a spare pair of shoes? I always do, because there's no knowing when the main pair might get soaked through, suddenly break a strap or an eyelet or something, or decide to cause some kind of heel pain or hot spot even after being well broken in. But I'm no good at living dangerously....