I'm 5'11' and around 165 lb, and my wife is under 5' and 106 lbs. We both have Sprinter kayaks. After trying several plastic sit on tops, we had to acquire the Sprinter because it's in a class of its own.
Fast, incredibly stable under way and seaworthy. Turns on a dime with rudder and lean action. Initial stability may be somewhat of an issue on the very first time the boat is used, after a couple of times on the boat, it's easy to handle. Secondary stability is amazing for a boat this narrow
We use a low back rest to reinforce correct posture. We paddle in flat water and open ocean, handling up to 4 foot swells in any direction, surfs swell without burying the nose while shifting weight. We don't surf breaking waves.
Windy days are no problem, the Sprinter tracks well with the rudder system provided. The adjustable foot rests allow for applying forward paddling technique and rotation.
The rudder can be set in two ways, depending on the desired sensitivity to foot pressure.
The boat's handling without rudder is tricky but possible, due to the rocker line which enables turning and surfing, but also makes the rudderless boat sensible to side shifting of bodyweight.
Forward and back hatches are appropriate in size and the rubber covers provide an hermetic seal. The day hatch right between the legs is very accessible for hydration and light food, I just fitted it with a mesh bag attached to the hatch cover.
I have to give the Sprinter a 10, because, for a plastic sit on top kayak, it does extremely well for the way we like to paddle and it adjusted very well to our different body sizes and weights. After Sprinter, a glass surfski!!!