No, have not been to an on-track event and have no experience. A couple members of the local SVTOA chapter recommended changing. From what I have read there is a lot of conflicting information on this subject. The bottom line that I can deduce is that it won't hurt to change it, but the fluid will have to be changed more often. The benefits of DOT4 fluid do not appear to be terribly signifcant, but since I have DOT4 in my possession I'm going to change anyway. See you at IRP!