Hydraulic will if rigged right give you infinite speed control but you have to do the controlling. ,Electric feed, I THINK,by its nature, naturally slows up when resistance gets harder. Think of the starter in an(old) car if you try to roll the car ahead on the starter while wheels are in gear. Starter goes way slower due to extra load.This is a plus for electric feed but hydraulic does work extremely well as a feed system.You just back off a bit on the flow when it starts to labour in the cut.
clgr