Yero:
As always, Lefox gives good advice - ride one. And yes, there are many things you can do to make it more long-distance friendly. Since you are likely an athlete and in good shape, the seat and pegs should not be much of an issue. You might look at Bar Risers - if not higher, farther back bars, Gel Grips, cruise control. But it depends on your build, height, fitness, etc.
The Buell is great fun. Fun enough to keep you interested for long rides. The sound, the engine, etc. It is also almost trouble free and easy to work on - Important for those on a budget. I had a great sport touring bike (FJR1300) before I got the Buell and I just love this bike (XB12S). I haven't done too many long rides yet. My longest day so far was 200 miles and I really had no problem other than some hand fatigue because the grips are a little small for my hands.
I will be riding tomorrow about 200 miles again. I own them, but haven't put the gel grips on yet, but I will be using a cheap little hand wrest tomorrow. I do plan on putting on something like a Throttlemeister later. Can that be added with bar-end mirrors?
Any suggestions out there for cruise control and some type of bar-ends or better mirrors out there?