Some questions about LA vs Toxic Rain atlas completion

I'm still deciding what I will be farming for the first two days of the league, but one thing seems to be a staple on every path I'm thinking of taking and that thing is fast atlas completion.

How does LA atlas completion compare to TR? Is LA faster but has a harder time going into red maps? If I need to do anything tougher in a higher tier map, be it a boss or an essence, will I have too hard of a time with day 1 gear? Is TR a lot slower?

LA is probably better for Breach, Legion, Heist and Expedition. TR is probably better for Essences, Harvest, Harbinger, Beasts, Blight and bosses. And they are kinda the same against Abyss and Incursion, right?

I am asking because I've skipped all leagues in the last year and a half. Ty!

LA is generally faster than TR, but TR is played more tanky.

Havoc on youtube has lots of videos on LA progression if you want to see someone doing it. Not sure about TR but it hasn't changed much for ages.