Vinyl vs Gunite? Well, that's up to you. But the advice that you don't push a builder to do what he doesn't do is sound.

There is nothing wrong with vinyl. It's less expensive, repairable, and doesn't require curing, doesn't require calcium in the water (though pool builders and pool stores insist it does), and can safely tolerate much higher total alkalinity levels. Liners can last 15-20 years before being replaced if they aren't abused. They can tolerate ground shifting because they are flexible and stretch, and the ground underneath them can be basically sand. It's easy to add lights or returns, too--I added two new returns after the season a couple of years ago to accomodate my re-plumbing my solar panels.

On the other hand, vinyl liners can be torn by improperly wielded tools, dogs and other animals, and by grossly improper chemicals. Too much bleach will fade them, too low a pH (too acid) can weaken them. They don't look as good as gunite, and patches can be ugly. You also can NEVER drain all the water unless you are replacing the liner.

Gunite can tolerate much higher levels of chlorine (if you need to do EXTREME shocking) and much more acid water--lower pH. They don't tear from dog's nails or a mis-applied tool. And NOTHING looks as good as a beautifully designed and finished tiled pool. If your ground underneath it is water-free, you can fully drain them for maintenance and cleaning.

But they require curing and you MUST be very careful about your calcium and total alkalinity levels. They will require maintenance--anywhere from 5 to 10 years apart. They can crack if the ground shifts and the patches are hard to hide. If the pool is emptied and there's a lot of ground water, it can actually "float" up out of the ground. And they cost more than vinyl. Repairing the underground plumbing is far more expensive and harder to access.

So it's your choice. In MY humble opinion, I believe that vinyl is lower maintenance than gunite/concrete/tile, and, if properly installed and the water maintained, I know they last 15-20 years (always get the thickest, heaviest liner you can afford that's available).

But nothing looks as good gunite/tile.