I too was wondering what to choose. We just bought are first AG pool and will be getting starting on the ground prep in a few weeks.

One dealer said foam bottom is much nicer and I think it may feel nicer too. But another dealer said no. The reason they said no was that the seems would eventually separate and you have to tape the seems too. And that I guess is very noticable (makes sense).

The one thing I do know I would like better about foam would be no worries about small rocks. I think we have decided on sand. Two of my friends have used sand and years later their pools are still fine.

I would love others opions and experiences.