I've ran a XX4 for 12 months and found the front wish bones to be the weak point of the car. (even broke one landing on all fours off a jump!)
I've since changed to an X10 infact a very familiar X10 that Jimmy reviewed (Chassis Number 28
) Only done one meeting with it so far which broke the carbon fibre steering link (which is now replaced with a steel link on the new cars!)