No cavitation out of the hole for me with the 14/19. Even with a new wear ring I couldn't rapidly go from idle to full throttle with the stock impeller without some cavitation. No increase in top speed on my boat.
I also have a 13/18 and the differnece between it and the 14/19 is nil. Same max RPM. You'd think the the 13/18 would increase the RPM, but it doesn't.
Let us know how the 14/19 performs on your boat.