I still use IMAP for my email and sync my calendar and contacts through MfE. I assume that MfE is primarily targetted at organisations with a company directory, so you can use company mailing lists etc which you may not be able to do in IMAP.

I still use Nokia Messaging, and I agree – it’s less than ideal. I actually downloaded this immediately when I got the phone, so I haven’t tried the built-in email app yet.

I can only speak for MfE syncing with Google Calendar, which it does perfectly. I have mine set up to sync my phone calendar with my Google calendar (which is in turn synced with my desktop calendar) every 4 hours. There’s no apps to leave running in the background, no alerts or anything, the MfE app just gets it done.