Re MO's review, I'd take it with a grain of salt because in Part 1 of the 600 shootout, they complemented the 636's ergos and handling: "Don't let my description scare you away though, the bike is actually surprisingly comfortable in every day life and doesn't feel like it is going to bite you ... That seat may be too steeply raked, but it's still comfortable to your tailbone after over an hour on the freeway." and "The riding position feels natural, could even be OK for day-long sport touring."
I say there's no substitute for sitting on it and reaching your own conclusions.
I was looking for a streetbike, and I was thisclose to buying a leftover '02 but I sat on the '03 for a while, and it wasn't as uncomfortable as I thought. Certainly, it wasn't too uncomfortable for me. I eventually chose it over the '02 as a streetbike because I thought the powerband would be more useful on the street than the 02's. (Plus, it will have a much better resale value, and it has extra stuff that I would have otherwise had to buy for the 02 like the rear hugger and the solo cowl).
So far I've only ridden the 636 for all of 29 miles (it started raining the day after I got it) but I haven't regretted the ergos in a half hour of riding (both freeway and street). Of course, the motor needs no further elaboration.
To be fair, here some things you might not like about it as a streetbike:
1. Taller seat height than the 02. (I'm only 5'8) I can flat-foot the 02 but not the 03 (my heel is up by about an inch).
2. Forward sloping seat (doesn't bother me too much).
3. If the steering is turned all the way to the right, it's hard to roll the throttle.
4. Stock settings on the suspension might be too firm for comfort on bumpy roads.