While I do not doubt both work well,I believe the use of minnows may limit the fisherman a bit.With plastic I can change colors,types of lures,and technique,minnows not so much.Minnows offer the challange of keeping them alive,and active,plastics require the fisherman to manipulate the lure.
I have noticed that on a day to day evaluation where I fish,I've did better than most live bait guys.One reason for this is nearly all the live bait guys move spot to spot more frequently than I do.I watched a boat with three older gentlemen ( known to be the local crappie pros) fishing the same lake I do.These men are strictly minnow men,their style is to cover as much water as fast as possible.
I'm more of the find the fish,and stick with them.nearly every outing,I caught more,and better crappie than they.Im assuming,they feel if something doesn't hit the minnow quickly,they aren't hitting of are not around the cover.I on the other hand,choose to anchor more,and switch up my lures untill I get a response.My thought is,in my case if I'm in crappie cover,it's best to fish the complete cover and column extensively before moving on.