I agree with melimcn, you will be much better off purchasing 8's and 12's. Depending on the workout, if it moves quickly, getting the wrist weights on and off, even though quick, still is not quick enough. I use my 8,10,12's for so many workouts now, and just would not want to bother with using the wrist weights. The cost of getting the 8's and 12's is nothing when compared to the convenience of having them.
However, I did use the wrist weights for STS when I needed in between weights like 17, 22, 27, etc.. There is often no way I can jump from a 15 to 20 or 20 to 25, and the option for in between weights in that range was a necessity. Some places do sell 17.5, 22.5, etc, but they are hard to find, and it gets VERY pricey in that range to buy all those heavy dumbbells. I have 2 and 3 pound wrist weights, 1 pound weighted gloves, and 5 pound ankle weights.
I can't say I use the ankle weights too often, they are mainly used for floor work, but you could add them to your ankles for step ups and step up varieties like in 4 Day Split.