Right now groups.io still appears to be the best option. They at least appear to be a professional org, are scaling up for the transition, didn¡¯t try to push malware/scare ads to me, and of course are not the FB that a few of you fear.
Alas, in less than 2 hours they¡¯re going to double their price for the transfer, and id be skeptical that they¡¯d go down.
I can initiate the move with at least some positive commitment from members. I¡¯m sure things will be different, but that¡¯s life.