Is there any difference in sound? Also, will maple necks handle sweaty hands better than rosewood or will there still be visible signs of use?
im not sure, but the action will be different
Jackson KE 3 Trans Black
Schecter C7 ATX
Siggery Custom

Axe Fx Owner
Maple to me has always had a 'cleaner' sound than rosewood. I also remember reading an article way back about Hendrix and he said the same thing. As a woodworker, I can only guess that it is because the maple is more dense, which will add to the sustain. The rosewood is less dense, which tends to absorb the sound. But both of these are so slight you probably couldn't measure it. It's just a feeling IMHO.
On the signs of use, maple will show more/sooner than rosewood but it will also depend, on how you play, how much you play, if you sweat more, etc. Look at the Strat that Hendrix used at Woodstock and you'll see what I mean.