D’oh! Keiran, I’ve just sold mine for £55 for both callipers!
I’ve still got the XT levers which I used if you could find the callipers cheap somewhere, the XT levers have the same adjustments as the speed dials (the modulation thing).
I found the BB7s very powerful and they felt great. A car park test of the levers and they feel 99% as smooth as hydros. As soon as you’re on the trail you don’t even notice it.
I used bog standard shimano outers, but filled them with a teflon spray beforehand, felt fine. If I’d kept them I would have used a couple of V-Brake concertinas between the brake arm and the cable stop, to cover the 1″ of exposed cable there. I did a super sloppy Glentress ride (the secret trails, a good test of any brake!) and some mucky water made it into the cable at the bottom. The concertinas would have stopped that.
I’d be tempted to carry a wee torx key with me for adjustments, if you need to adjust on the trail when your hands are cold and the calliper is covered in mud and grit, you might find the adjusters a wee bit difficult to turn. A torx key would solve that issue.
I only sold in the end because I was trying to sell the whole bike and thought the cable discs were putting people off as I didn’t get any interest…