I don't know if this'll help, but I'm often two up with my daughter and there is no real difference, my America still loves the twisties and powering up hills, but then my daughter is still growing and at the moment only weighs about 7 stone (roughly 98 lbs)
Personly, I think the America/Speedmasters make ideal light tourers
We will be going to Dent in July which will mean carrying a tent and stuff for a weekend, so I will have a better idea then, but I think you want an answer before then
