I have a Pelican Enforcer 120X and during my first few times out, I tested the limits of the kayak in shallow water. Definitely not a standing-up kayak, it's waaaay too unstable, however it's incredibly stable when sitting. I'd have to be trying to dump myself to roll over in it.
Test your limits in shallow water without gear. Wear some swim trunks! Once you know your limits you'll feel a lot better!