First time the front end lifted on me I thought I was going to crash. Just finished a turn and was mostly stood back up, gunned it and the front lifted off and the rear tire started to skid to the side. That was mere minutes after I put the roadster delimited tune on my touring. Not sure if I did the ramair yet, but I had the 3-to-1 muffler on.
I know some people may have just had the front suspension unload, but you can feel it in the bars when the front wheen loses traction. And if you're unskilled at wheelies like me, you can feel when the front wheel come back down. My left pannier guard is still bent from comin' down too hard from an accidental wheelie.