I personally prefer external firewire burners. In particular for anything high volume, and most certainly for any high volume on a slot loader. Lots of businesses are burning (sometimes several) cds/dvds on their imacs every day, and they can wear them out in sometimes under three months flat.

Also if that drive does die, you just walk out and buy another one and are back up in 30 minutes, no need to check it in for service even.

I work for the Department of Redundancy Department