I've had my flexideck dirtsurfer since xmas last year, and I prefer it every time over four wheeled boards, and its great.
The all the 2003 models have disc brakes which are excellent - I have been bombing down the quantocks at 45mph-50mph, and been able to brake with control using the calf lever.
There is also space to adapt your brake and add a second rear brake if you want to. I know Tom who posts on this site has done that to his dirtsurfer.
Some other advice to newbies on dirtsurfers would be not to look at the front wheel when riding as it will put you off, and there is info on dirtsurfers at http://www.mkyd.com or http://www.dirtsurfer.com - i think.
I'm just starting to learn to kite board with my dirtsurfer now so I'll let you all know how I get along with it.
Garthy