Sorry, I've never owned one but I've tuned a lot of them (I didn't vote because I don't meet your stringent voting requirements). We use lots of Axis blocks and have never had anything but positive experiences, all the way up to about 500 WHP. We do probably one a month for the last 2-3 years. Ron is awesome and so are his engines!
Edit: someone should move this to general discussion as it has nothing to do with proven power.