touratech sump guard

Has anyone gone uk off-roading using a touratech kevlar carbon fibre sump guard ? How tough is it compared to say an aluminum one ? Will it take a good knock ect if aluminum is better can you recomend one for (94) f650.
cheers
wedgie

Have a word with our very own Dakar hero Chris (used to be a fat twat) Emerson , I think he had one on his 650 rallye.