Until now at least I found your race, background, deity or class (you can multiclass so that would be a mess) does not change substantially the play, mechanically wise, only the dialogues.
The Mythic paths are what largely change the shape of the world, at least based on what we´ve seen in the first chapters, and some dialogue, alignment and other decisions you made by roleplaying during the campaign, not constrained by what you choose at level one. I prefer to shape the story by my decisions ingame, not by my character sheet.
Even if I like reactivity based on your character traits, I think that makes more sense this way. I mean, there are +50 class choices, 9 races and 12 deities, realistically it is not feasible to shape the world based on all those options unless you are making a visual novel. We were lucky about the stretch goal in the Kickstarter to add more deities and dialogues because we wouldn´t have that either.
And hats off to Owlcat for putting them in, wasn’t supposed to sound like a criticism.
I do think I would personally prefer fewer classes and thus a tighter dialogue, but that’s possibly just me.
The Mythic classes are a bit weird, so far I have only had the choice of Heaven and a dash of Aeon. I just haven’t encountered anything else. Presumably due to being chaotic-good and choosing a lot of “good” answers, but it just means my play through currently is a little cliche(?!). That said I’m still at the story point prior to Dresen (just did the swarm encounter). So it sounds like there is still plenty of water to flow under said proverbial bridge of options.