Derailure pulley for cross

[rustychain]

I upgraded my road bike so my old SR went to my cross with the crank being replaced with Campy's cross specific crank. All works fine but after using the original pulleys and some replacement pulleys I'm still not satisfied. The original SR pulleys collect mud and gunk like mad. My replacements had bearings but did not shift as well. I'm looking for quality and durability in nasty cross conditions. Were I live that's clay mud that sticks like glue, grass, snow, ice, and the occasional horse poo. My Super Record derailure is stock but for new pulleys. I'm grateful for suggestions.

[schmiken]

MT Zoom ones are quite good, don't have any issues with those or KCNC on my MTB.