Well I went to see Kye at Greenhithe yesterday (Pendle agent) and have now had a couple of days driving.
wow - what a difference! My 1.9 105 now flies - it really is like driving a different vehicle! drove down to 2Worthing today to go windsurfing and it was like driving a sports car! Pulls so much better, no need to change gears so much (but flies if you do) - I really couldn't be happier and definitely recommend him.
Took about 2 hrs. First he plugs in his laptop and takes a reading. You then go for a drive and do some exercises where your drop down to about 1000 rpm in third and then floor it until it red lines. The feedback to this is sent to Martin, who does his magic and then downloads in back to Kye, who then installs it. You then repeat the redlining exercise while he does some checks - and that's it!
If you're thinking of doing this - get it done!