Ive paddle the Mamba and does pretty good on class V. The main difference in the seat is the amount of safety features and adjustment. The creek Seat gives you the step out pillar and more places for gear but is harder to adjust which is good cause you don't want it to come loose, and the play seat is lighter easier to adjust the seat position for a quick adjustment for better play. If you plan on Class V get the creek seat.
Add the Quick release belt. Now you wont get the chest harness effect the green jacket has or the extra creeking armor but you'll be able to tow boats, do tethered swims and tie in to an anchor from the belt.
Why you love kayaking: That's like asking why do I breathe... it's become necessity. I do it to survive. It has become a lifetime fitness activity. Fitness for my body and my mind. I do it because it makes me better, and therefore I want to make it better. I do it because people depend on me to do it, because I have become a conduit so they can make themselves better. I do it because I am passionate about it, and I believe if you are not passionate about something in life, doesn't matter what it is, then you have let a piece of yourself go.