I know there were a few people that switched out these from their comp 918's. Have they held up? Any problems with them? Anyone busted one yet?

 

i've got 1500 miles on mine so far with my 224/224 .581/.581 cam, not a single problem whatsoever.

I've only heard of one breaking of the spring, which is thought to have been caused by a bent valvetrain peice. (either valve or pushrod, can't remember now) I talked to this guy when I was doing some research on the rev springs before buying my set, he said he went back with another rev-1116 spring replacement and had zero problems since.