I'll play devil's advocate here and say that I much prefer shimano's sprung system of countering shifting friction and derailleur springs. I have a set and I have found that they make for very easy shifting, and feel similar to a Simplex retrofriction lever (DT shifters mind you). I found that the suntour models would ratchet past where I wanted them to be, and I'd be trimming after shifting. I'm using both shifters with 8-speed cassettes and chains, although different derailleurs.
I'd just use whichever one I liked better if I were you, and most BFers really like the suntour ratcheting. The shimano sprung levers are somewhat rarer as well.