I've got the enduro version of that bike. They're very nice. Frank White had sold the company and the new owners decided to redesign the ATK. The previous model was very tall and at 6'2" I had trouble touching the ground. The new design was to address that problem. According to Lee at the factory the new owners were business people and not into bikes. But they did a great job with the new design. They subsequently sold the factory back to Frank White. I was at the factory talking to Lee during the first change over period.
The cross over frame model has a low seat height and feels like an old school motorcycle. Yet with long travel suspension. It slides and mono's very easily and has very quick steering, It was designed as a woods model where the older model was more of a desert bike. The later models of the cross over frame came with Ohlins PDS shock and Paoli forks which by reports are a much better setup than the earlier white power forks and shock. They're a somewhat unique bike and very unusual and cool in my opinion. The way the bike handles I wasn't surprised when they bought out a dirt track model as it would lend itself very well to that application. They are also quite a light bike, but feel a bit heavy to ride because of the heavy flywheel of the motor. On the scales my '95 (The old design) surprisingly came in 5 or so kg lighter than my KTM520 yet riding it the gyroscopic forces tend to tire you quicker.
If you ever consider buying one you would be pretty happy with it. Ron Woods can get 70 horses out of those motors, but you do lose reliability and like all race motors they can grenade. But those Rotax motors are strong and over engineered. When I did the clutch in mine, the clutch hub ran on a bush on a bearing and then another bush on the shaft. Roller rockers in the heads, etc.