Have never tried the MF but I have the MXR and it's a good filter. It was a 'great' filter until I managed to get my hands on a 3Leaf Audio GR2 & Wonderlove. Those things just blew it out of the water I'm afraid. I still use the MXR filter with an octave & fuzz for 'synthy' stuff but for out and out funk you can't beat the 3Leaf filters. IMHO of course!
"Women and Rhythm Section First"
3Leaf Audio Club #71 l Team Trace Elliot #165 l The MXR Official Club #69