If you get a bigger one, be sure it has a plug! I had a cheap big one last year and it was a pain. Couldn't lift it to empty it, and had to bail first. BIG pain. I'm either going to get a smaller cheap one this year, or a bigger more expensive with plug. And yes, Sam loves his. Lies down in it.
The first summer we had Jack, when he was about 1 1/2, we got him a plastic Walmart pool. He WOULD NOT get in it, but loved to drink from it. He also chewed on it and one day all the water drained out and we came home to him running around the back yard carrying the pool!! It was quite a site!
He does love to get in streams and puddles, though.