Epoxy paint is a 5-10 year solution. Properly cared for, plaster is a 25+ year solution.

I do 5-10 epoxy paint coatings a year, here's my advice;
-Do not completely smooth the pool surface, especially steps. The coating is slick, so a little tread is a good thing.
-Follow the prep directions to a "T".
-Do not apply the coating when temps are above 90F or the surface will be in direct sun. It will blister the surface. Yes, I have painted jobs at night and I have used large tarps to create chade.
-Wear a respirator and have air movement. The air down in a pool is dead and can create a bad situation quickly. We use a 36" drum fan to circulate the air.
-Someone mentioned above they did touch up and it was a different shade. You need to do a complete coat in one application. Subtle differences in humidity will effect the sheen and shade. Plan for that.

I'm probably forgetting more than that, I'll reply again as it comes to me.