2.1 is 15 months through it's 3 year support lifecycle. That means it certainly has had a bunch of fixes to make it more "stable", but of course those are all in 3.0 too :)
@Nick_Craver@shanselman@mayankdotnet 3.1 will be out shortly (Dec) and will be LTS, giving a fresh 3 year support term. Moving from 3.0 to 3.1 should be trivial.