...there's no advantage in having a SATA optical drive...the advantages lie in using SATA hard drives.
Well...there is the advantage of using the slimmer cables...but I don't consider that worthwhile as a pretext for changing the connection on a device that still will perform whatever it does...at the same speed.
If you have no intent of using SATA hard drives, I see no reason to consider utilizing a controller card.
I believe that SATA optical drives exist only because motherboard/system manufacturers have decided that PATA/IDE connectors are a thing of the past. Newer motherboards have been produced for some time now...with only one or no IDE connections, while the number of SATA connectors has increased.
I could be wrong but it seems to be a technology change primarily designed for hard drives (which can operate with greater speed/efficiency) and optical drives are just along for the ride because IDE ports/connections are going the way of the dodo.
Some opinions, http://www.dslreports.com/forum/r19445719-...-optical-drives
IMO, it's always good to have a controller card around that can facilitate connection of both SATA and IDE devices on a system. And...if you're going to have one, try to get one that is known to be reliable (not all are).