Firstly, Welcome to Ribnet!
The good / bad discussion will start a heated debate, guaranteed! Whether it helps or hinders will depend on the boat, engine, load, sea state etc etc etc. Personally, I've removed them from 2 secondhand ribs so far 'cos I didn't like what they did to the handling. there are others out here who swear by them.
Two things are for sure - you will get on the plane quicker due to the lift, but you will loose a couple of knots because you are dragging more stuff through the water.