AS has been mentioned...BW burpies are enough for most people. I would only use a weight vest with burpies under two condtions. A. training a VERY fit fighter. B. As part of a fight specific circut (5 exercises, 1 min each) for a guy who was fighting a bigger, stronger opponent, who liked to clinch (say Randy). The purpose of condtion B is to get him used to carrying the other guys weight. I would also have the same guy do weighted drills (say, sit outs, bridging) with the weigh vest.
"Wax on, wax off, Daniel San"!