I'm more of an envelope filter guy. I never really got the hang of the rocker pedal, but I never spent much time with one either. Squire used a wah on the Fish and parts of CTTE good effect. He later got a Mutron envelope filter (GFTO era?) and got some great dynamics with it on several songs - Wondrous Stories, Future Times/Rejoice, Don't Kill the Whale, On the Silent Wings of Freedom...