We had a 5.7m RIB with a 115 Opti, which we used in Poole a lot.
With a speed limit of 10kts, we found that we were pushing half the water in the harbour in front of us. I installed Smart Tabs (bought in the USA for half the price) and the RIB would plane at 10kts and dramatically lowered the fuel consumption.
In general use at higher speeds, they had no detrimental impact on the handling, but in the rough, seemed to smooth out some of the bigger impacts after being airborne!
They are a fit and forget item that needed no specific maintenance.