Here is my review of Rainbow white sapote, which is regarded as one of the better cultivars. For those that don't know, Rainbow is a "census designated area" near San Diego in California. While the fruit were better than Kampong (a cv from Asia) I was still disappointed. It's just a bland flavor to me, similar to corn. Could they improve as the tree ages? Maybe...
This cultivar has nice large fruit, but large seeds too. By mass, seeds are around 10% of the fruit, but by volume higher. I would eat the thin skin if it wasn't toxic (according to internet) which just makes this another hassle. Fruit go from rock hard to ripe and cracking quickly. White sapote have creaminess and gelatinous texture going for them, but then bananas and persimmons are just superior. I also can't get past the slight bitterness.
Then there are issues with cultivation, like scale outbreaks, fruit fly susceptibility, invasive roots and tree vigor. Would still like to try Younghan's Gold, Sunset and Skipper though.