Anything 4 A Ride MTB Club / Race Team
Graeme Spreadbury
   Ok so it's not a Mountain Bike, but this bike has done more for my race pace than any of my more costly MTBs. I first bought this bike in 2005 with a view for using it to get to the station. I chose the P6 version of the Sportster as it didn't have the suspension fork (what's the point on a road bike). Since then I've actually been riding all the way to work and generally using it instead of the car (if the weather is good). It's had a fair few upgrades since new, all of the drivetrain has been upgraded to Deore, LX and XTR. Most of these bits and a lot of the other bits on the bike come off my MTBs when they get upgraded, hence the XTR front mech. I also bought some new wheels for it and some Continental Sport Contact tyres which are ace.
   The best upgrade on the bike though is undoubtably the Brookes B17 Special saddle. Its the model with the copper rails and rivets. It took about 150miles for it to "break in" and now it is the most comfortable saddle I have ever had. You can ride on it for over 6hours one day then get back on the bike the next day without even knowing you'd been on the bike the previous day. It really is that comfortable and lives up to all the hype it gets. However it does weigh almost twice as much as the other saddles I use and it takes a bit of care, hence why I don't have one on the race MTBs.
   I've also done a couple of tours on this bike and it is a pleasure to ride and could quite easily handle all the weight of 5 days clothes, tent cooking stuff etc.  
   I will be upgrading the frame and fork soon though. The current frame does flex a bit (ok it wasn't designed for touring, but it flexes on the commute, when you peddle hard) and the fork is a bit of a heavy weight.
Updated: I now have the Planet X Kaffenback so this is being put back to its original spec and the good bits put on the
 Sportster P6 
 Aero Steel
 Single Digit 5  
 B17 Special
 EA50 130mm * 0deg
 EA50 Flat
 Mech (F)
 XTR M960
 Mech (R)
 LX M582
 Old SPD