I put a pool in almost 20 years ago. Decided on fiberglass over gunite. I've always had a gunite pool and had to deal with acid washing, cracking, rough surfaces. Now with the fiberglass I've had zero issues. It insulates better, chemicals don't leach out and nice and smooth on your feet with the gel-coat. The negative with fiberglass is you are stuck with what they make. Mine is 16x40, would have liked bigger but the trade off was worth it.
I have always maintained myself, never a service. Use saltwater and very easy.
I will say my biggest regret is not getting a rectangle over a free form so the automatic cover rides under the coping rather than on top of the concrete. I've had to replace my cover 4 times now.
Go to https://www.troublefreepool.com/forums/ for lots of help. Most important is a good test kit and NEVER trust a pool store.
PM me and I am more than happy to tell you my thoughts if you want.