why do some dislike clutches?

sorry for the delay in the reply been busy all weekend. the 1/8th oval racing is 45laps or five minutes which ever the sooner and with the 9xl 51 spur 18 pinion direct drive i would get 62 laps out in practice runs on 4cell flight power 5350mh bearing in mind you are on full throttle 80% of the run. when installed the elektri clutch on the same set up it produced 86 laps track time.
this weekend was a race meeting and after each race and some warm up laps i recharged the lipos and i had used 2900 to 3100 mhs for this track time hope this helps
btw the inner oval barrier length is 85 mts