BB -
The house I bought last summer has an aggregate patio around the pool. My biggest complaint about it is the tiny pebbles that break loose and end up in the pool (and in the house on the hardwood floors). I'm constantly vacuuming them up from the pool stairs and on the pool floor around the stairs. I doubt they could do any damage to my liner, but you definitely know it when you step on one. Sealing the aggregate will probably help my problem, but that project is way, way down my to-do list!
Like others have said, lots of complaints at first from the family about how rough it is on their feet, but I don't hear about it as much as I used to, so maybe their feet have toughened up a little! That said, whenever I redo the pool/patio, the aggregate will be replaced with pavers or something else.
Hope that helps!
Jeff