I rode an XB9 Lightning last weekend. I would assume that it would be similar to the Firebolt, with a bit different riding position. I've only ridden my CB550 for the last 2 years, and it's been a loooong time since I rode before anything else. That being said, I was amazed at how different the Buell was.
First thing I noticed was that it shook. A lot. Not buzzy, not vibration, straight up shaking like a paint shaker. I've heard lots of Buell guys talking about this, so I was somewhat ready for it, but it was more than I expected. Not a bad thing, just something to get used to.
Next thing I notice is what brakes are supposed to feel like on a bike. Almost felt like I had never ridden before because the were so sticky.
Yes, it is short. But I felt more like the bike was an extension of me than something that I was just hanging on to. Something I found almost comical at first is at idle the engine feels like it's gonna die - if it was an inline 4. At first I wouldn't let it idle at a stoplight because it felt like a CB right before cutting out
Oh yeah, the one I rode had an aftermarket muffler, so it was LOUD. Really loud. To each his own on that one...
There was something that I didn't like - the shifter and the brake are short and too far down. At first I had to look down to hit the shifter. I couldn't find it by feel. I'm sure there's some reason for that, but I'd look for a replacement that sticks out a bit more, or fab up one if necessary. Same for the brake.
Also, I'm up in the air about the belt drive. Some swear by it, some get rid of it and do a chain conversion. The older models (03) had crappy belts, and many upgraded them, but if you're buying new you shouldn't have to worry about it. Buell has addressed this issue and the new ones are supposedly unbreakable.
I'm not too concerned about power and wheelies, so I can't comment there. I also can't comment on Buell reliability. You always hear about the bad ones, but the good ones just keep on being ridden. I have heard nightmare stories about dealership woes with Buells. Some HD dealers only deal with them because they have to, some are great. (But with a SOHC in your background I'm sure you're quite capable of taking care of anything yourself).
I'm on the other side from Jeff - The Buell is the ultimate for me. In fact, after seeing that bike two years ago I started my quest to get up on two wheels. After seeing the price I got my CB550 instead
The Buell site is
http://www.badweatherbikers.com/