We used two of these recently for two weeks on lakes, canals and the ocean. The size was perfect for 2 adults, 1 adult/2 kids or 2 kids plus all of our gear. It was extremely stable and smooth on both rough and still waters. I would 100% recommend this product.
The first thing I noticed when we took it out was the size of the cockpits. Both the front and the back are longer than the cockpits on my Prowlers. There is also a hatch between the two which gives even more distance between paddlers. It is virtually impossible to hit paddles even if you are totally out of sync.
The next thing I noticed was the speed stability. This thing is fast for a SOT tandem, a function of its length and relatively narrow beam. Even with the narrow beam it is amazingly stable. While it will fly, it likes to go in a straight line. Turning can be a chore, if you are not doing it in unison.
Although we only installed the center oval hatch, it has plenty of room for storage, plenty for an overnighter. Overall, it is a very nice tandem for covering distance with a good load. It is by far, superior to the run of the mill SOT tandems.
Feature-wise, I cannot say enough good things about this boat. I've got mine set up with two large ovals, and two 6" rounds. I use the rounds for cameras, keys and the ovals for everything else. Out of necessity paddling with two kids, I always pack a kayak cart, extra paddles, food, water, dry cloths, towels, cooler, and often stuff that my friends cannot fit in the Tarpon which can only handle two 6" rounds. The ovals are big enough for a small child to crawl into the hull which makes available the entire boat for storage. There are also quite a few choices for the kids to sit, again, unlike the Tarpon. Every piece of hardware and rigging is screwed into an insert or blind hole as opposed to through hole for nuts and bolts in my Tarpon. This makes is impossible to ever leak. The top surface is in a rough matte finish which provides incredible grip for slippery muddy shoes while the bottom surface is silky smooth. The deck bungees are all quick release. There are 4 handles which really comes in handy for such a big boat. Also there are two paddle keepers. The two molded in cup holders have bungee retainers, a great feature.
Stability wise, it's similar to the Tarpon, but that's expected in a wide SOT tandem, even though it's a few inches narrower. With two kids constantly jumping off or climbing back in, it never feel the least bit tippy. The kids feel so comfortable with the stability, they often spend their time standing in the boat. It even felt stable being broadsided by a 1-foot boat wakes. In fact, we now make it a point to broadside every boat wake we can find just for fun.
Speed and tracking are both far superior to the Tarpon. That's not surprising since it's the longest and narrowest SOT tandem I know of. On the flip side, because of it's un-rockered hull, it is a bit of a pain to turn (by myself). With the rudder system though, the 16.5 foot boat becomes a 10 footer. It won't win any drag races, but will cruise comfortable all day.
I recently sold the Tarpon knowing that I'd never want to paddle any other SOT tandem. My kids are strong enough to handle their own boats this season, so, I picked up a Carolina 12. As they get older, I'm probably gonna get another single boat so they could each have their own, but I don't foresee ever parting with the trusty no-brainer Zest II Exp.
Other reviewers are right that it is heavy to load and hard to portage. I have a Chevy Suburban which makes travel easier as I drive from Tulsa, OK to Destin, FL. The only reason I purchased this was to spend time in the water in Florida. I can imagine that if you want to yak in other bays that it can and work well. Hope this helps, but I would purchase in a heart beat. My wife gave it to me as a birthday present after doing lots of research. Buy IT!
It is too bad that Ocean Kayak discontinued the Zest for a few years. It is the boat we really wanted to own. Fortunately they came back with the new model, which is even better than the old. Get one, you will love it! The only disadvantage is that is is a bit large and heavy. So what? You get what you pay for. Want to boogie on the big waves and lounge around in the quiet waters? You can't do that on a surf ski...