Bought a 20# vest on Sunday. Did a couple cardio sessions in it, did a double ended speed bag sessions in it, and then, on Tuesday, did my first full kick training session in it. You don't think of 20# as being a lot of weight, but it REALLY makes a difference in your movement and balance. Tonight, I'm planning on doing a full hand/elbow combination training session in it, probably with some more speed bag work. Can't wait to see how much of an impact regular training in this thing has on my stamina, balance, and quickness.