I don't believe you can get a definitive answer on lengevity. Most of the issues I have read about on this forum and seen firsthand involve delamination. (The coating seperates from the concrete) As I indicated, I would attribute that to the thouroughness or lack thereof of the prep work prior to application......but there are other variables at work, also....Sun, water, freezing, etc.

The point in my post is that, if you and the pool builder can make a deal you're both comfortable with, there would be no loss to you in waiting a while to see what the concrete looks like next Spring or Fall. If the appearance becomes acceptable to you, you know you have a surface that is permanent rather than an overcoat that may give you other issues down the road.