Very hostile. It only happened to me on mastodon. A few content creators I follow went to gab when gab became a mastodon instance. The instance I was on was beginning to break the protocol and firewall off gab's instance.

I said that people should have control over their own timelines, I understood they may not want gabs posts in the global timeline but at least give users freedom on who to follow.

I got slandered as a nazi and rallied on by the tusky developer. 5 minutes later I was banned.

I also checked out gab itself and people there were way friendlier. These days I use neither has I have 0 faith in the mastodon ecosystem.

Here its very much the same pattern that if a platform is censorship resistant the people are much friendlier since you dont get hate mobbed at an attempt to deplatform you. And the hateful people can't ban all the regular ones.