I'm no Husky expert, I only own the one. My understanding is that the whole bike bar the crankcases, cylinder, head and engine internals are the same as other Huskys. Even clutch and gearbox are the same. Parts are easy to get, except for the 4 stroke specific bits. These aren't unobtainable but generally very expensive.
I agree with what you say about the performance. I had a 450 Husaberg and I don't think it has anymore power.
Cheers, Grahame