I've ridden a 510 and a 650 husie, tone of power and very light. problem is that there are very few aftermarket parts, and reliability is not the greatest. Parts are hard to come by and very expensive.
We've just sold 4 of them in the last week or so. Just got an extra $300.00 rebate form Suzuki on them. I think the price was a little high on them, thus the lower number of sales. At this price now, we're buying them from other dealers.