The "rule" for APUG is to match the physical print or transparency as closely as possible with the display. Negative scans should be mostly un-manipulated except for some sharpening/contrast/brightness/CC adjustments. "Finishing" a neg scan in PS for display in the APUG gallery goes a bit against the spirit of things. For a non-APUG application, whatever floats your boat.

This kind of discussion is allowed on APUG, as it relates directly to scanning for the APUG portfolios and galleries, and as long as it doesn't grow to exceed the scope of the OP.