Once I got my properly jetted I had no problems with it. It starts first kick once warm, two or three after sitting for days / weeks. The suspesion isn't up to motocross specs, but for my skills it's been fine. The bike may be a little heavy, but after riding it and adapting to it it hasn't been a problem.
Some paarts can be a little hard to find, mainly body work which is why I got most of my stuff off that popular auction site. Most motor parts are from a KX250 motor, so no issues there. Any other parts I've been able to get from my local Kawi dealer.
The bike has been easy to work on w/ no major issues. I enjoyed how nice it was to work on a bike that was so simple. Changing jets is a breeze. Replacing swingarm bearings was a simple task.
It depends on the price. I paid around a thousand for mine a few years ago, but I had to put some money into it to get it up to snuff. I wouldn't pay much more than $1200 to 1500 for a decent one.
By the way, when you get on the pipe, the motor absolutely rips!