I would not buy this pull buoy again. It's a little too bulky and just feels like it's too buoyant. Makes flipturns more difficult than they should be. I'll still use it, but overall I'm not impressed.
I expected this buoy to be a little bigger than the Club Swim or TYR, but it is not, so my legs still drag down in the water more than I expected. In any case, the shape does make it a bit easier to keep in position.