We've owned the Easky 15LV for several years, and generally are very happy with it. We've paddled it on lakes, rivers and ocean bays. The feature I like most is the way the hull slices through the water with almost no bow wake. Very efficient, and gives a smoother ride in choppy water than other boats (like our Eddyline Journey) that tend to slap and splash on every wave.
The narrow beam and smallish cockpit make it feel tippy on entry and exit, but that's the trade-off for a sleek hull. The only time it's a problem is in the ocean surf where quick entry/exit must be made between breakers. The seat has a minimalist design with a folding band for a backrest, but it works and is reasonably comfortable. There is a small water bottle holder directly in front of the cockpit which is very convenient. It has a watertight cover so can be used for a cell phone, watch, wallet, etc.
The real wet dog in the design is the skeg. It's spring loaded with a thin elastic string in the skeg recess in the underside of the hull. This is connected to a string with a catch near the cockpit. On dry land with all components clean, the skeg operates correctly, but lazily. There is a lot of drag in the linkage, and not much pull from the elastic. In the water, when things get wet and gritty, the skeg sticks and the elastic doesn't have enough pull to operate it. I've tried tightening the elastic, but then it's too difficult to retract....the leverage is wrong. Luckily, the Easky handles well without the skeg.
Overall, this is a great all-round kayak except for the useless skeg.
The seat is comfortable for my usual 4-12 mile trips (with short bathroom breaks). The bow and stern compartments are not completely watertight, but only took on a little water even when I was in a rescue practice daylong class that involved deliberately falling out of the boat many times.
So secondary stability is good, but primary stability not quite as good as a heavier or wider boat, but it doesn't bother me at all.
This boat is not as easy to handle on twisty turny narrow rivers, where most people are using 10' boats.