When I went to a track day at Donington in September, I spoke to a suspension company bloke from K-Tech who said if I removed my shock and sent it to them they could service it for something like £150 (I think, completely forgot) - it's the later remote reservoir type.

Is it worth replacing it with something else and re-springing or would it be better to service the original? I fancy something with more adjustability...

What would you adjust on it?

Preload, rebound, damping? Tbh I'm not sure what can be adjusted on my current shock, it's absolutely shagged. I took it to two different suspension blokes at two different track days and both said it needs a service or replacement.

the std shock has all of these - preload and rebound damping. There is not a compression adjuster on them, but if there was it would be on the canister.

For a budget, RS250 or a rebuild of the oem. - Yours is just going to have weak pissy grey water in it instead of lovely fresh oil. The spring will be tired too after 20yrs of abuse

http://www.revsracing.co.uk/

I used these to service my shock, including new spring and set up to my weight, can't remember exact price, but way cheaper than what K-tech quoted you. Put it back on the bike and was amazing the difference. I would definately recommend

John at Revs has done stuff for me before now, very good on price and service.
I went a different route and bought an Ohlins for £300, which had just had a service. Better damping that you're ever going to gte out of a std unit. bear in mind a service and new spring on a std unit is going to be £150-180 and you still 'see' a std shock the Ohlins/maxton etc I felt was better value. Plus i'll always get back what i paid for it and bung the std shock back on when/if I sell the bike

My WP shock was serviced by MCT when they sorted my suspension. It was 7 years old, they serviced it, changed the spring to suit, rides like a new bike. For my money, pcik up a secondhand Ohlins/WP and get it serviced/sorted by a pro. If you are going to keep the bike, if not, stick with what you have!