I would always use weight, no question. A double bouy'd cheap Danielson pot on a flood could lift up and float. I would also stay away from pots that have doors that swing and touch at the bottom of the pot. You get one inch of mud or sand on the bottom and that door either doesn't swing open or sticks open. I always use pots that have an elevated ramp into it. Then you also dont lose crab as other crab enter and open the door. That's why in my experience a McKay always outfished any other pot. Now several manufactures make good crab pots that are very similiar to the early McKay's. 
You happen to have a link to the type of pot you're talking about?
