FWIW, EAGLE, the T100 is a version of the Bonneville ("Bonnie"); the plain-Jane Bonneville is the base model.
Nerd alert: The Bonnie went from a 790cc to 865cc motor in 2007. Slightly more power and torque (67hp at 7200 and 52ft-lb at 6000 in 2007 v. 62hp at 7400 and 44ft-lb at 3500 in 2001). I think the 5hp bump is negligible for a bike weighing 500 pounds wet, but ... you/he may notice that lower torque output. Happily, the 2001 torque peaks far lower in the powerband.
Ted, to my knowledge, there are no major bugaboos with the Bonnevilles. It's an easy bike to work on, too. It's carbureted, not injected -- can be a minus in cold climates. And
THIS PLACE is just tremendous for parts and customer service.
Overall, it's a great bike for anyone who's not into hardcore sport-riding. Very comfortable, good linear power delivery, fantastic looks, great MPG, low insurance, and the world is your oyster for aftermarket stuff to make it your own. I was looking really hard at the T100 and the Thruxton; old man body ruled out the Thrux, and something about the Speed Triple just kept making me walk over to it. Otherwise, I'd have gotten the Bonneville for sure.
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HERE for discussions of joys/concerns.