I have one and am getting two more for Christmas.
I use them on Lockie. The fit is generous, he has large and there is plenty of room in it. They last up to 2 1/2 to 3 hours with the soaker. You could put another booster in easily if you wanted to. They do start to wick if the soaker gets very wet with us. I've never been able to use the outer again after one use as the inside is always a little bit damp. They are gorgeously soft and fit beautifully though and i love the colours.