John
for normal X10's shooting recurve IMHO you would be just as well with steel. The X10 also seems to be tougher than the ProTour. When I was shooting normal X10's I had fewer breaks. However, as has already been pointed out here, X10's, particularly Protours, do not like straw bosses and I have read elsewhere on
AIUK that Easton won't warranty them against this damage in the UK.
I found that the Nano XR and Nano pro do not have the same issues with straw and the same with Cartel Triples. We know many archers who shoot triples into straw week on week without any problems.
Regarding improved FOC, I only found 0.2% difference.