I don't care for SOT kayaks, because you're going to get wet. I fish earlier and later than most, during colder water months and prefer a SIK kayak.
Getting in and out would have to go to the SOT kayak.
As for stability...I'd have to say it a toss-up and a matter of keeping your butt on the seat. Doing something silly is going to put you in the drink. There are SOT kayak companies that feature being able to stand and fish. Jackson is one of those companies, but I'm sure there are others.
I have fished out of my 12' Pungo for the last 3 years and never once came close to tipping. It has a large cockpit making easy exits. Being a sit in I can also paddle upstream through riffled which I doubt most sot can
"Sit in" or "Sit on"... I think stability depends on hull design regardless. By nature, a sit on is less stable due to higher center of gravity... but most sit ons are wider to compensate for that. Of course, making them wider also tends to make them slower. Kayak hull design is a very complex process, which contains many trade-offs, compromises, and balancing of opposing characteristics. What it comes down to is this: there is not ONE BEST design. You might have a design that is the MOST stable, or a design that is the MOST maneuverable, or a design that has the BEST tracking, or a design that has the LEAST hydraulic drag, or a design that is the LIGHTEST and EASIEST to handle out of the water, or a design that has the MOST convenient gear stowage... and on and on... but you'll never find one that is at the top is ALL of these categories. And for that reason, kayakers as a whole will never agree on what is the best kayak out there (although some have strong opinions). This is one reason that many serious kayaker have multiple boats, as has already been alluded to here. There may be a best kayak for a particular type of fishing... although that still involves a LOT of opinion. Some sit ons are incredibly stable, some not so much, some sit ins are incredibly stabil, others not so much. You tend to pay for stability with weight, especially in sit ons... but there are boats that pay for stability by making other compromises. Some say sit on tops are too wet, but in my Hobie, I only get my feet wet when launching and landing... I never have to sit in water. Only time I get wet beyond my feet is if I'm getting spray from significant chop (Nimisila last Sunday, 25-30mph winds, first time in a long time that my clothes got a tad wet in the Hobie). I guess all this is really just to say that there is no simple answer to your question.
By the way, just for the record, I've never paddled a sit in kayak at all. I did some research, decided that a sit ON would meet my needs the best (I haul it to North Carolina and use it in the ocean as well). I don't tend to get into arguments about which is better, sit in or sit on... because I know that both have their place, and their advantages. I only pipe up when I don't agree with an absolute statement someone has made. If someone says "all sit on top kayaks are too wet" I can disagree from experience. Just find what's best for YOU, and how YOU use it... 'cause if you're looking for what's BEST overall, you'll get a thousand different answers.
One other thing. Experience is a factor. Who could ride a bike the first time on. When I first got my SOT, I felt very unstable; I had a hard time with anything behind me and almost broke my spine trying to turn 90 degrees at the waist. Now, I move around like I was on dry land. I'm sure I can stand up but so far I haven't needed or wanted too.
I have only paddles the cheaper $300 SIT so I should not compare them to my two SOT kayaks. But the SIT had little to no room for gear and you could not mover around at all in it. I have never tipped ether SOT kayak before. As for getting wet in a kayak I have no idea why you think a SOT is any wetter of a ride. The only way I can see you getting wet is if your paddle is to short and you have your drip ring in the wrong place. The only time I ever get water in my kayak is when I am washing the blood out of my kayak and the water just runs out of the kayak through the scupper holes. And with my Hobie I can stand and pee out of it. If you want to anchor and fish with a SOT you can turn sideways in the kayak and put your feet in the water on the hot days to stay cool. I would also say a SOT is much safer if you did tip over. I would hate to have to try to get my legs out of a SIT after tipping over in the middle of the lake. Then trying to get all the water back out. Last summer up at Erie one of the guys I was wish had a big wave hit his SIT twice and fill it up with water. That sounds a little to scare for me. I had a few waves come over the top of my SOT and it was no issue. It ran back out just as fast as it came in. That was in 3-4 footers.
There is a third option that I havent seen anyone mention, a hybrid. Which is a cross between a kayak and a canoe ie Wilderness Systems Commander and Native Ultimate. Cant speak for the Ultimate but my Commander is very stable and dry. I can easily stand up in it, havent tried fishing in the standing position yet.
Wilderness Systems Commander 120
The Commander 120 is a nice looking rig. I quess another factor is how much accessory gear you want to add. Some kayaks have better platforms for rod holders, fish finders, live wells, general storage, etc., etc. My ocean has lots of room and good mounting areas. When I go out it's normally for the entire day. I want a comfortable seat, I want fresh live bait all day, food, drink and as KeithOH stated, I want to be able to pee without going ashore (I finally mastered that). If you want to take a multi-day float you need lots of storage; a kayaks load capacity then becomes a factor. As for getting wet, Summer time isn't an issue. As I've said before, if you plan to fish in cold weather, you need to dress accordingly. Price range is going to narrow a persons choices and his/her attitude about maintaing their yak. If I pay $200.00 I won't mind scooting into the water from any surface but I going to avoid any damage to a $2,500 Hobie Marage Pro Angler so transportation and water access points will be an issue.
ive got 2 sot kayaks and bought them specifically bc i thought they were easier to get in and out of. Im a bigger guy at 6 5" and 240 and im my price range i couldn't find a sit inside that was comfortable. I do get wet in mine in the summer, but if i put the plugs in no problem.
Picked up my 2nd Wilderness kayak for my daughter and my buddies to use. A Pungo 120 for me and. Pamlico 120 for them. Think I'll stick with the Sit in's for now. Now just need some time off work to get out!
Outdoor Hub mobile, the outdoor information engine
Yeah don't forget about the 3rd kind of yak- the hybrid. I have had SINKs and SOTs and now I leave them both at home in favor of my Native Watercraft Ultimate 12. Its stable, open like a canoe so you can just set your stuff anywhere if you want, and its as easy to sit side saddle or get in and out of as a SOT. For me its the perfect boat. But it took me years to figure out exactly which boat would work best for the way I fish and the places I fish.
As for a SOT being a wet ride, isn't that what they make scupper plugs for?
But it took me years to figure out exactly which boat would work best for the way I fish and the places I fish.
I thought that was worth repeating.
I've been fishing out of kayaks for almost 20 years. The WAY I fish and WHERE I fished meant everything when it came to what was the "best" kayak. The difference between paddling a river and a lake is night and day. Even on different rivers, different types of kayaks excel. Some rivers a one man ODC pontoon is the "best" while others a heavily keeled sit on top kayak is "best".