Sharpening is rarely effective; like polishing a turd. You can't make ice cream from $#!+ (apologies for the continuing theme there).
Sharpening only works when the noise level is very low, and it only works is a sort of edge-enhancement mode (and not very effectively). And a little goes a long way. Adjust until you think you might have gone almost too far, then cut that at least in half.
The limitations it has sort of dictate that no sharpen algorithm is really very good at all.
A better idea is to start with a good HD cam with good glass.