Cycling "Spin" Class - To Kill or not to Kill

I do not teach my cycling class like an aerobics instructor. I teach it like a cyclist. One that is going to have a killer 40 minute workout usually. This is a noon hour class that consists mainly of the over-40-but-in-good-shape crowd. Here is the setup of my class today. It may have been a bit harsher than usual (but not much) which ponders my question to those who take cycling classes: Is this class too harsh? Do I deserve the name Killer Kevin (not that I take any offense at the name)?

5 min warmup - :05

Muddy it up! *tension to the point where your cadence is a hill cadence 60-80 rpm
30 second seated push followed by :15 seated sprint
30 second seated push followed by :15 out of saddle sprint
2 sets - 3 min total - :08

1:30 easy - tension back to start - 9:30

1 big turn up
:30 hard cadence - :30 standing flat
5 sets - 5:00 total - 14:30

Muddy it up!
:30 second seated push - :30 second standing jog - :15 standing sprint - :30 standing jog
2 sets - 3:30 total - 18:00

2:00 easy tension back to start - 20:00

2 big turns up
:30 85% effort sprints :30 recover
5 sets - 5:00 25:00

1:00 easy tension back to start - 26:00

Muddy it up! - Option to go tougher to the rider
:30 seated push - :30 stand easy - :30 standing jog
6 sets - 9:00 total - 35:00

5 min cool down/stretch - 40:00 - End Class