I did one a short while ago. No kneedowns, but I wore a fair portion of my toe sliders off and my back tire is scrubbed right to the very edge.
It was £89 for the day, and tbh, I don't think I could have ridden that track any more. I was shattered!
I even made a little video...
Or this one if you want to skip the pre-amble...
All in all, I reckon the bike was more than capable. I was in the novice group as it was my first track day, so I'm not saying I'm the best rider, but I was keeping up with and on some of the bendier sections overtaking R1's and R6's. All on my 12 year old commuter!!!
It must hurt to be overtaken by a £500 granddad when you're on your £5000 sportsbike!