I have no direct experience but I can say I've been contacted by a board member who replaced his magneto with a Surefly and shortly thereafter returned the Surefly in favor of CPI. I'll leave it up to him to self identify if he wishes.
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.
Harmon Rocket II -SDS EFI - Flying
RV-8 - Flying
1940 Taylorcraft BL-65 -flying