Big slot down the middle. Narrow slot doesn't work for everyone. Don't get up on the nose. Stay back over the slot. I like saddles which don't have much curve in the profile. I think that curve can push the rider forward. Zero numbness on 10+ hour rides is what you want. Anything less is unacceptable. I don't think fitness has much to do with numbness, one of the problems being that the fitter you are, the more hours you can be in the saddle. I think most modern saddles benefit from 2°-3° of down-tilt.
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