[Dovecot] Upgrading 1.2 to 2.x

Hi

In an unscheduled maintenance window next week, I will have the opportunity to upgrade to 2.x should I wish to do and provided I can get it working on stage first.

My questions:

I've seen a lot on the list about the rock-solidness of 1.2 but also some people saying that some versions of 2.x better than others. Is there a recommended version - I don't need bleeding edge, I'd prefer stability, or one most of you can agree on?

What am I missing by not upgrading?

A few months ago I tried to convert a Dovecot 1.2 config into 2.1 and wasn't very successful. Any tips on how to go about it?

Thanks.

Simon