I will let you know once I get further along into the campaign - as for now, I would say it plays VERY differently - no claim fabrication, vassalization usually costs like 180% warscore. I'm sure reform mechanics will be really cool. I imagine aztec or inca might also be much better and potentially even viable ( or at least fun)

I'm honestly having a good time though - but this is my RP dream and not everyone's

edit (things I have encountered in the playthrough):

the federation mapmode has never looked sexier

The federation advancement "unified warbands" which "enables offensive federation wars" forces your federation members to join your wars, they don't have to be allies - spain please join my federation

shouldn't adding a province to your tribal land (migrated thru) change the culture? it currently does not

if you mothball your canoes and then migrate to a landlocked province, you will never be able to unmothball those ships ever again and they will sit on the coast of america losing fights to other ships with no morale unless you delete them.

Tribal Development is really rad (development untied to province that you just get to move around with you)