I personally prefer the Piefed platform
What community are you talking about? thebrainbin.org is kbin or mbin (hence the name), and lemmy.cafe is lemmy (also reflected in the hostname). I don’t see any piefed variants.
Lemmy software is older and more stable than m/kbin. I am surprised at how many bugs litter Lemmy considering its age, but it’s still more usable than m/kbin.