Anyone have experience migrating from in-house mail servers to gmail?

Hey all! I'm an IT guy (Among other dev duties) at a small office that runs it's own mail servers. As I am a fan of the KISS principle, I'm heavily swayed by the idea of switching our email service over to a gmail - I'm wondering if anyone here has experience doing the switch? Or alternatively, any cons of using gmail from an administrative perspective that might not be obvious?

Things I'd like to do:

• integrate sign-on with our OpenLDAP server
• import existing mail (dovecot)
• never have to think about it again

Edit: formatting