My pool times without pull buoy improved as well. But only after I glued two pull buoys together.

No small pull buoys for me anymore!
I do all the warm up and cool down with pull buoys too. Only first lap without after the dive. I still have to learn to dive with the buoy already between the thighs.
The pull buoy and paddle advice was the best swim advice I ever got. Two years after I converted to this method I have more then 10% time improvement over long distances.

And the best thing is, I am still improving every month.

One question Doc,
Do you like the shape of the red pull buoy in the picture best? I have 1.5 normal foam pull buoys glued together but the red one on the picture looks like it elevates the hips a bit more because of more buoyancy under the pelvis. Or am I thinking too much now?