The buell falls into the class called Streetfighters:
1. Harley no longer makes Buell, they are owned by them, however the design team totally left HD. So you can't classify it as a harley.
2. Buell does not compete at superbike competitions, harley has always had their own racing competitions only for harley bikes.
3. The bike is nowhere fast enough, or agile enough to be considered a track bike.
4. The only good thing about it is the vtwin sound, and (ugly) looks.