EQ pedals are very useful, and i cant do with out mine.
i've tried a few now, including the ones you mention.
the mxr 6 band is very slightly more noisy than the standard boss, however it is much nicer to use (leds and long faders) and sounds more musical. based on standard pedals i would take the mxr 6 band.
then i modified my boss pedal. after than the boss was /alot/ more quiet, and slightly more transparent (it was rather transparent to start with though) and now i use my boss exclusively.
i'll sell/swap you my mxr if you like (still got that painkiller?)? or to be honest, if i was to be buying an eq pedal now, i'd get this one:
http://www.buildyourownclone.com/EQ.htmlnever tried it, but i'm pretty sure its going to be good.
i dont find i need loads of bands... the 6 on the MXR was more than enough, i don't think i'd like less than 5 though.