getDataFromTree vs Automatic Static Optimization

[jaexplorer]

Hi,
Sorry if this is a noob question, i'm new to Apollo and can't seem to find good documentation surrounding the tradeoffs.

From my understanding, we want SSR and SEO so wouldn't getDataFromTree be the best choice all the time? Even at the cost of performance?
It is also my understanding that Automatic Static Optimization does this for you and detects whether you have queries to run or not (does this mean you don't need to worry about loading states with components with queries?). Or you can manually include getDataFromTree only for pages that have queries.

Also, apparently you can do ssr: true somewhere above cache in the parameters - whats this do?