Well you have a different XT to me,the bolts took seconds(like they do)getting the plastic shrouds off to get at the bolts what a ball ache!!!.

As for the amount,hmmm having done similar with other bikes 5mm is a lot,drop forks too much and the front will start to tuck and push the front end when you ride it hard and on a wet day you can be in a world of pain,I've just been out out on it and it's not bad,it doesn't do anymore than it did before,well not strictly true,it does steer a tad quicker,but now takes a lot less effort and a pleasant improvement,what's really needed is a set of light weight wheels but god knows where I'm going to get those.