Well a slant from a veteran of one track day...
I was nervous as feck when I did Mallory in September 10, my bike was only 6 months old (£7500) so I was crapping myself I'd bin it, it only had 2.5k on the clock.
Im not a quick rider as anyone who knows me will testify and probably never will be, but I did enjoy it once I settled down, I certainly wasn't the slowest and there was only two groups on our day due to low numbers so we had novices and inters with track bikes in our group, I even overtook a guy on a track bike after he was holding me up for 2-3 laps, yes ME
Thing I hated the most was the overtaking on both sides of you, bikes buzzing you on the inside when your just setting yourself for a corner was unnerving to say the least.
As time went on I commanded my space a bit more so it didn't happen as much.
Overall no knee downs or peg scraping on my big lardy tourer but I enjoyed it and learnt that my brakes were actually bloody good if you pushed them, I was outbraking quite a few at the hairpin which was nice
I'll defo do another, on what bike I'm unsure.