I used them to learn Winging on our family inflatable SUP board. It worked great and i still have them for the moment another family member will try to Wing surf.
I got them from Duotone but they are the same as the ION one.I can recommend them for just cruising around and still have a upwind session.
I bought the drift stopper installed it on a slingshot X breed sup in an effort to turn into a windsurfer for kids (to function as a central fin or dagger board)
The Slingshot is a better way to go IMO. The drift stopper is over engineered. To many parts and it's prone to breakage. Have used both and prefer the Slingshot.
To stop drifting DW it's best to place the drift stopper in front of your feet / standing position. Jibing and tacking will be easier by changing your feet fore- or backward.The big advantage of the drift stopper is that you can change the position easiely. Play a little bit around and you'll find the best compromise.