Apart from an unfortunate transom incident in one, which was otherwise an excellent hull ... the worst had to be my first RIB a North craft Sea sport 5.8 .. It wasnt so much the hull, but the fit out.
It had a 135 two stroke on it, and water lapped over the transom at rest, as it only had one sigle/double jockey on it so, the bow was too light, it used to fly all over the place and slap and slam on every damn sea, then it chine walked on flat sea when you went full bung, and thats a scary mofo of an experience let me tell you. punters had to sit on the toobes, and it was the scariest white knuckle ride for my passengers, but strangely, lots of them loved that
The elephant trunks leaked too, and the fuel pipe floated up in the tank, and took me a good few trips to work out why I kept conking out when the tank got to half way down .. still,... a steel nut stiched to the suction hose sorted that ... but why oh why do you always find these things out in a sea thats just blown up to a six
It had a heavy 'pull' on the steering too which put you in fear of your life if you let it go at full bung
.. It was a hardy thing though