Yes Ive tried them. In the rear they are excellent and a definite improvement. In the front I pulled the axle joining pin through the CVD after a couple of runs - I think it is to do with the transfer of rotational force when on steering lock. Others have problems of elongating the pin holes as well (think there is a thread either in here or Losi off-road re this). I have just bought some Titanium CVDs and axles from a company in the UK (Titanium racing and hope these will do the job - much much lighter - even than Alu and much more durable - can get them mail order from Apexmodels.co.uk). The interesting thing to note with these is that the CVDs and axles are constructed differentlr. the CVD has the ball on the end and the axle the socket thus meaning that the pin holes are further from the edge of the cup so should prevent pull out - but I guess titanium is much harder than Alu anyway!! Dont see why MIP couldnt change their design to account for this (apart from the cost of re-tooling!!)
Rich