I love hand planes, just like others on this forum...
I have a PM 20" planer with a Byrd helical head.
Its tuned just right. The surface comes damn close to my best hand planes.
maybe a quick swipe of 220 and its there. The good helical heads, in the right planer / jointer are a huge break through in ww.
I had a Makita Lunchbox planer, kept new blades in it, finish was smooth as glass. I would not suggest running hardwoods at max width capacity and deep cuts. U have to work with the planer, listen to it, adjust accordingly.
AS for cuts per inch on planner with stratight blades? I cant think of any good reason to slow down the cutter speed, other than if you are forced to feed the stock slower, or maybe have super knarly grain.
Also, a planer can produce a uniform thickness along the entire board... incredibly difficult with a hand plane, specially when the board is much longer than the hand plane.