I don't know about performance difference, at least measurable. However, one thing I like to do is use a different color between the first and second coat to use as a wear indicator. If the first coat is blue and the topcoat red, I know I need to really start thinking about a bottom job when the blue starts showing through.
By the way, don't forget some extra coats at the waterline and the leading edge of the
keel and
rudder. Those areas wear fastest.
Rich