Just throwing this out there: does anyone have a pool like this, or have you considered it? It's just like a plastic bedliner in a pickup truck.
http://www.rhinoliningsindustrial.com/p ... d-pw/22/46
Last night I was watching the Mythbusters prove that this stuff is (small) bomb proof when applied to a framed wall I had heard of this being used to line pools before, but a search of the forum just turns up spdas's pool (see this thread), which is a bit atypical in many ways (it's made out of a shipping container) and so his experience really isn't applicable to most people.
Once I thought about it, my initial impression is that it seems like it would be the perfect coating for a gunite pool. Abrasion- and impact-resistant, easily patched or sanded smooth, non-brittle, no calcium to leach out, etc. It might bleach like a vinyl liner eventually, but hey, white pools are nice too I'm not in any hurry to chip out my pebbletec, but if I needed to replaster I might look into it.
Any of you pros have any experience with this stuff? Anybody know how well polyurethane holds up to chlorine?