I think if you are looking for a good all day kayak you can't go wrong. Only downside is that it is heavy. I can move it by myself, but I don't like to....
Heavy and long, so tracks through anything - wind, waves, surf.
LOTS of storage space.
When completely ocean swamped can easily get back in, hold course, and paddle in without floundering.
Great storage for multi night camping. The thick poly means it will resist oil canning and last forever.
Hard to load/unload on car for most.
Integral rudder was always getting bashed on something.
Doesn't like to turn via hip or rudder - think school bus, not sports car.
Out of production for many years now it would be a good used beginner lake/ocean kayak.
I should add that I am a T7/8 paraplegic, completely paralyzed from the base of my sternum downward. As such, I have no trunk stability of my own -- if I lean in any direction, I will tip over. So, I retrofit all my kayaks with my own very high, very rigid backrest, usually bracing it against the inside rim of the coaming. The backrest reaches up into my functional musculature, which allows me to brace off the backrest. Since all my stability ultimately comes from the boat, the boat must have significant resistance to tipping. In testing numerous boats, the Atlantis (the Dagger Halifax is the same hull, but with conventional rudder) offered the best resistance to tipping in the 24-inch class. Did I mention that I'm also extremely top-heavy in my body? Any boats that I tested under 23 inches wide offered little to no resistance to tipping.
I find the Atlantis to be a little twitchy on initial stability, but surprisingly strong on secondary. To ratchet the stability up another notch, I carry a 20-pound leaden bar velcroed in the forward section of the rear hatch. This bar really lowers my center of gravity.
I see that some say the Atlantis is maneuverable. For me, that depends. If you keep the integral rudder, which turns at the rear end of the keel as if it were an airplane tail flap, locked in the straight position; then it takes an Act of Congress to turn the boat. I can not edge the boat of course, since that requires hip control. I'm sure it would turn better with edging. I mounted a Cascade Designs trim tab on my Atlantis, which gives me hand control of the rudder, and when I use the rudder to make a turn, the boat is very maneuverable indeed.
I find the Atlantis to be a hard tracker, and for me, it almost ignores wind. Perhaps the lead bar has something to do with it.
I wanted a plastic boat because I get in on high, solid, wheelchair ground, and then ski-pole myself in my boat down to and back up from the water. I fear that I would break a glass boat, and it just doesn't seem right to abuse Kevlar the way I buff my plastic. My second choice in a long, reasonably efficient touring boat is a Storm by Current Designs, but the cockpit is smaller and I couldn't fit my size 13 feet in it very well.
For a safety net in my Atlantis in rough water, I mount inflatable sponsons far enough rearward that they don't interfere with my paddling, and also high enough that they clear the water by an inch or two. Then, if I lean the boat over, the sponspons catch and provide ludicrous secondary stability without any drag during normal paddling. It's an idea that seems to work great in practice. I paddle Lake Superior a lot, though I haven't ventured into more than two-footers yet with the Atlantis. It is superb in two-footers, and seems to be totally unfazed even when waves come from the beam, thanks to the shallow-arch hull. The twitchy intitial stability is a plus in waves.
I did move my seat rearward about two inches in the cockpit, which makes for an easy butt-first entry. This probably also makes for better wind balance to reduce weathercocking.
Personally, I really like the integral rudder over the conventional. It doesn't catch wind, but fulfills its function nicely. This may be a little weird, but when we installed my trim tab, the rudder cables weren't tight, and I test paddled the boat with slack cables. This allows the rudder to fly freely for 10 to 15 degrees in either direction. I found that I actually prefer this. With tight cables, the boat tracks too hard for my taste. Even a minor course change required major paddle effort. Now, I can make minor course corrections with an easy paddle input, so I don't have to keep reaching for my trim tab or try to horse the boat over with the paddle.
The only reason I don't give this boat a ten is that it weighs practically 70 pounds. I don't take it on solo paddles, because it's a bear to load by myself. I have different boats for different purposes, and I use a Yukon Expedition by Prijon for solo paddling outings. It's much slower than the Atlantis, but lighter and more stable, and extremely maneuverable on land due to the pronounced rocker, but I digress.
In short, if you want an excellent plastic big guy boat, with really strong secondary stability, and a high volume deck in front of the cockpit for big feet, plus excellent rough water handling characteristics, you can't go wrong with the Atlantis or Halifax.
I have mostly had it out on rivers and creeks and have found it very stable, easy to paddle boat. The rudder takes a little getting used to. Unlike a regular rudder, it takes a stroke or two for this one to react, so you need to be patient enough to not over correct. It is effective in compensating for any weathercocking.
The last two weekends I've had it in salt water. I cruised the islands off Cedar Key on a calm day with no problems at all. I flipped it to practice my wet entry and the boat wa very stable with a paddle float. I made it back in on my first try. This weekend I did Salt Run, through St. Augustine, then to Oyster Creek. I was able to handle 20 mph headwinds on my return trip. Again I was very stable in the 2' chop. I like the boat very much and am really happy with it's performance.
Initial stability was quite good, and adequate even for beginners. Because of that, I thought the secondary stability would suffer, but not so. It was easy to get it up on edge (way up on edge) and keep it there, rock solid. The initial stability is stable enough that I would flyfish out of the Atlantis as I do out of my much more stable Edisto. By comparison, the Perception Eclipse has much lower initial stability and about the same secondary stability --- a net loss in my opinion.
The Atlantis responds well to leaned turns, actually turning faster and easier at times than my 14'6" Dagger Edisto (which is very flat-bottomed and doesn't lean turn worth squat). The Eclipse also responds well to leaned turns, as well as the Atlantis. The Atlantis seemed to weathercock some, but it was easy to trim that out with leans.
The Atlantis now has Dagger's integral rudder. I think the integral rudder is a great thing, and my next touring boat will probably be a Dagger because of it. It takes longer for this rudder to have an effect on your course, but once it kicks in, it works well. It's not as effective as a traditional over the top rudder for steering, but it's more useful for fighting the Atlantis' tendency to weathercock. My favorite thing about the rudder is that the pedals have a very short throw. Even with the rudder turned all the way to one side or the other, My leg on that side wasn't straightened all the way out (like with traditional rudders), which allowed me to still brace effectively with my feet and allowed me to transfer paddling energy to the boat effectively as well. When locked out, the pedals were very solid, almost feeling like they weren't rudder pedals at all (unlike a traditional rudder system, where the pedals often have a lot of slop in them with the rudder up).
Storage space seems adequate for long trips, and the boat probably tracks even better when loaded with gear. However, the boat handled well without a load, too, which is sometimes a problem for bigger boats.
Speed was adequate, though the Perception Eclipse, being a bit narrower, seemed quite a bit faster when I was paddling hard.
Overall, I think the Atlantis is a great plastic expedition-sized boat. I think it beats the Perception Eclipse by a hair, but your mileage may vary. If you need a big boat for long trips (or luxurious short trips!) and can't afford a composite boat (or want the abuse-ability of plastic), the Atlantis would be a great choice.