I am in a similar position. I used to post or engage in meaningful discussions on reddit almost every day. I was already reading reddit prior to the digg exodus, but I truly jumped to reddit when digg v4 landed. I never went back to digg to participate.
Oh well. I'll be on instances here I guess.
All of these and then some.
A small part is that I'm supporting the underdog.
It's not created by a company that sells ads.