Nah it’s grand. I did it last year and the year before, can’t make it this year though. The only real hills are coming out of Waterville and Molls gap after Kenmare, but neither are bad really. I went up Molls Gap in May with full camping gear, just long not steep.
If you get good weather its a nice day out and people are friendly. I did it in 7 hours 11 mins last year including stops, I’m no roadie :) I took my Jake with slicks on which was fine.
Both times I have flagged a bit by Sneem, then picked up by Kenmare with a 2nd wind from about 80 miles on.
Damn I wish I was going now!