[Dovecot] Server & move to Dovecot

Hi,

I a currently running a server which is using uw-imap server which currently has 190 users. I am looking to move the server OS and the imap server to Dovecot Imap Server. We are currently using mbox as the default mail file. I have a couple of questions to ask.

1. Would it be better if we moved to maildirs during the server move?
2. All current mail files are in a directly called /export/home/mail/%username. How would one configure dovecot to use the above path?

How points to any good FAQs would be great.

Thanks

Kevin