Hi there, as Craig said, the Mamba has more planing power compared to the Grip, it's made to get going fast and keep speed well - especially in mushy conditions. BUT - the Grip 92 will also have better and earlier planing over your Quad 89. The Rocker of the Grip is actually not too far away from the TriWave rocker, so generally we've made a step in planing over the previous Quads when we've changed to the Grip. I would make the choice depending on conditions you sail. If you have good waves a lot, then the Grip, if you sail in cross-onshore a lot, then the Mamba. If planing power is 100% focus, then Mamba for sure. OFO Grip 92 is at 36.8cm, Mamba 94 at 40.4cm, but the Mamba has half a cm narrower centre width over the Grip. Hope this helps! Cheers, Klaas