Sir G. sounds as if carbon is the perfect choice for your prefered discipline. Not had a carbon frame myself. Last 2 roadframes have been Alloy and they were both stiff and responsive. Downside is comfort. Back and sides feel fatigue earlier compared to what happened on my last steel frames (731OS road and 853 MTB). Not a problem though as now i Like to race XC which is 1-2 hours so dont need to ride any more than 2-3 hours in training