I went from the KF2 to the XB2 and was more consistent, i swopped from the XB2 to the YZ2CA and I'm quicker and still consistent.
Hands down for me the YZ2CA has been the best car 2wd car I've had. i had the YZ2 and didn't like it, to be fair i didn't give it a lot of time, it may have been as good as the CA but i will never know