I've got the same frame, paid 300 quid for it a couple of years ago. Only ride it a couple of times a year as its horrible off road. Very fast on the climbs and flats but slow as hell on the downhills because the frame is so stiff and twitchy. I'm really tempted to change it for a light alloy frame for the extra comfort. Being so stiff it does my back in too .
The worst mistake I've ever made was to do the kielder 100 on it, it nearly killed me !
Unless your after a super light twitchy race bike my advice would be a good alloy frame, mine is a 17 inch and weighs 1200g so is only around 200 to 300 grams lghter than a good alloy frame