i have seen a WCR go, it was fast but not ballistic, but that engine was new and had just been run in. the track i am going to run the engine on is a high speed track so a good topend motor is needed. from what i heard modded sirio based motors produce awesome topend power. i can get both the LC12 standard and sirio WCR for roughly the same price so im undecided on which to get, if anything the sirio WCR includes a new pipe so thats a bonus.