I weigh 230, I'm 5'10", and I've paddled both.
The 2015+ Jackson 4-fun is a pretty fun all day river running boat. It's more river runner than playboat by far with these latest changes. They changed the tail shape up a bit, lengthened it, and added volume. This means the boat isn't nearly as interested in stern squirting as other boats. Good for running more exciting rivers and water, not so good for river play. Yeah yeah it can be done, but it can't reasonably be done without a notable amount of exertion, so for downriver play I'd count it out for that. Surfs good, runs rivers good, decently fast, rolls plenty fine. If you've got a good roll, the 4 fun will roll just as good as any other well done Jackson kayak. I've taken it to the Bend WW park. Plays around pretty fun in the bottom hole. Not really great for cartwheeling, not miserable. Fun boat, but if you're looking to playboat, not the flavor.
The 2010+ Jackson Superfun is a BIG boat. 70 some odd gallons. It's REALLY wide. It surfs great, but overall, just a bit of a tub. Plays okay, doesn't roll great as it's so wide it's a lot of boat to turn over. Decent in a hole. Not great for river running as that big long flat tail gets grabbed and squirts you out or flips you over. It does stern squirt alright so that's pretty fun. Overall though, it's just not that great of a boat unless you're a real brute and no other options exist.
I would personally recommend just going with two boats: A boat to make hard things easier (Karma), and a boat to make easy things harder (Rockstar). These boats that try and shoot the middle just wind up not being great at anything in my experience.
The new Rockstar is a really fun downriver play boat that I'm all about at your build. The 2014 wasn't bad either, although not as friendly for getting vertical. The 2016 is really quite friendly in good amounts of water, the 2014 is even more friendly as it's got a bit more volume and it's placed a bit higher up and more central to the paddler.