I have played with TM RAC MuscleBack Irons for years and found they give me a solid strike when its swung easy but a wrist trembler when thin - but I am sure my old clubs felt like that when thined!
I find the blens i better and even considered the combo set where the higher irons were cavity -...
I always play with a No 1 in comps - My Initial is C so I mark a C and then a colon : Looks like a smiley face - helps to smile when i swing - good reminder to have fun and enjoy each swing