XT disc brakes

Smudge said:

I've seen mentioned DOT Fluid and it's compatability with disc brake kits for bikes and was interested to know whether DOT fluid is compatable with Shimano's XT hydraulic disc kits?

You need to check the Shimano spec's for that. Automotive brake fluid isn't the friendliest of chemicals and might damage seals, paint and whatnot.

Quoted post said:

I've been suffering from a fairly spongy brake ..I've tried bleeding it a number of times and replacing the fluid with fresh Shimano Hydraulic mineral oil.

It's rarely the fluid as such that's to blame, so simply replacing it isn't likely to do you any good. What you need to do is to get rid of any air bubbles that are trapped in the system. Given the low volume of bike brakes this can be rather tricky. One suggestion is trying to bleed the brakes while turning the bike at different angles, that might help in getting to bubbles that have gotten stuck somewhere.
Long shots would be bulging brake lines or flexing brake handles.

Quoted post said:

I was also a little disappointed with the stopping power of the disc. My previous V-brake set-up was far sharper.

That's not something you hear every day. Many brake pads require quite vicious braking to "burn in" before they perform as expected, are you sure you've done that step right?

Quoted post said:

Does anyone have any suggestions for improving the feel and stopping power of this disc (pad/replacement rotors etc.)

Pads aren't that expensive. Buy another set, read up on burn-in and see what happens.