You will need to find out what model. I believe there is the mx440, x440s, x440, c440, e440 etc. Also what year? is it new. There are already some great posts here describing the bike. Most seem to love it, however, reliability issues have shown up. It seems like the problems have been corrected for 2001 and 2002 and most that have delt with the factory support say it is unmatched in the industry. I am getting ready to take the cannondale plunge on a x440s. I ride mostly agressive desert trail riding and easily can get 20 to 30 miles away from anything and feel secure that the new cannondale will get me back. There is a large price difference in the models, the x440s seems to be going for 5500-6000 and the x440, c440, and e440 are 7000 to 8000. As strong as the cannondale may be, I have a hard time believing it is as powerfull as your 520. There is no replacement for displacement. the new ones come with ohlins forks and shocks so I would guess it was at least as good as the suspenders on the ktm.
Theres my 2 cents.
--marc