Simplex retrofriction are the best DT shifters of all time, I still use them on two bikes. Mind you, I am so fucking old that using them is instinctive.
I have used Simplex Retrofriction levers and they were the best friction levers I ever tried but although I wish to stick with DT (if I go that route)...I am not sure whether you can use them with 10 speed.
Simplex retrofriction are the best DT shifters of all time, I still use them on two bikes. Mind you, I am so fucking old that using them is instinctive.