Wicking and sweating are different.<br>
Wicking is the transfer of moisture from one absorbant surface to another. If you have a cover with leg bindings that are not totally repellant, then they will absorb urine and then those wet leg bindings will touch absorbant clothing and the clothing will absorb the moisture and you'll have a wet spot as the wet transfers more and more to the clothing.<br>
Sweating is when a cover is breathable and evaporates moisture through and creates a humid dampness to the outside of it. It's like when you get sweaty and your shirt feels ever so slightly damp. If you keep sweating too much, the clothes go from slightly humid/damp to actually wet. If you sweat slowly, then your clothes stay just damp feeling and have time to evaporate some of the moisture before getting truly wet.<br>
Bummis tend to wick at the leg bindings when the diaper is more than damp. The cover doesn't sweat unless there is something wrong with the waterproof layer.