JMCraig

Actually, I'd disagree slightly with the prior post (just trying to make your life complicated!). 1" of stand-over leaway is enough in my opinion. Even fully loaded, you should be able to balance your bike just fine with only one foot down (with one on a pedal, you're a lot taller over the top tube than you'd be with both feet on the ground).

A bigger frame does a number of things for you: more room for stretching forward if you want it (you can get a shorter stem if you want to be more upright--that's what I did); more room for rear panniers without them hitting your heels; and the fact that the frame angles on a bigger frame are generally slightly more "laid-back" than a smaller one.

But, here's the real key in my opinion: a touring bike should track like...well, like a touring bike. It should be simple to ride with no hands and you should be able to move your body around without affecting the tracking at all.

I ride a 23" frame with plenty of seat post showing on my "racing" bike (and I've got a long stem too). On my touring bike, I really like my 25" frame even though the seat post is pretty much right down at the bottom of the rational range (and the shorter stem I mentioned above). Be sure to try a touring bike with a pair of panniers on a rear rack if you can (otherwise hold them up and do some measuring to make sure you've got heel clearance).

I've found my touring bike extremely comfortable to ride (I used to ride it 30 miles to work, car-pool home, car-pool in, ride home--the round trip just took more time than I had). The longer tubes seem to soak up the road shock. So, what worked for me was to get the biggest one I could fit.

Ride a lot of bikes. Choose one you can steer reliably with no hands and that has room for rear bags--and, if it comes down to it, ride the next size up just to be sure.

Good luck!

J