[Dovecot] Dovecot 1.1.x and 1.2.x differencies

Hello,

I have been using successfully Dovecot 1.1.x for about a year now. It has been very stable. Now I'm uprading that same system to newer and more powerful hardware and I was wondering whether it is good idea or not to switch to Dovecot 1.2.x series. Could anybody direct me to feature comparision document or explain here main differences betweeen thos two branches?

-- Veiko