I think ablative paints are very good providing you sail a lot. Sitting in a marina is not where ablative paints belong. The problem with modern paints (as far as their power to deter growth) is what is no longer permitted to be used. Tributyl tin is outlawed, some once available chemicals are now only allowed to be painted onto 500+ ton ships.
I don't want to advocate using environmentally sensitive agents, but some of the paints available in third world countries, still contain powerful agents. For example Singapore Red is still available in some places, some of the Malaysian paints made by Jotun are simply amazing in their effectiveness...but they may not be sympathetic to the environment.
The big names are expensive and may or may not last longer, especially in tropical water. But there are many cheap paints which may cost only 50% of the dear brands, yet may be up to 85% as long lasting.
Not much of this will be of real benefit. But buy what you will; preparation is vital..smooth is good.
Keep us informed.
"if at first you don't succeed....Redefine success"!