This may help; it may not.
For my general 3-D work, I use a .125" ball end mill (2 flute), with a stepover of 0.010" (about 8% bit dia). Because the stepover is so small, I will let it cut that way up to 1/2" deep. The cutter has flutes up to 1/2", so I might as well use them and not waste time using a larger roughing bit when I do not need to.
Most of the wood that I cut is Ash, which I believe to be harder than most maple.
I am using a PC 892 router @ 23,000 rpm, and usually cutting at 140 IPM with this setup.