Not sure of the exact model number on the LaCie, but it was similar to that one. Mine was a couple years old and I've since given it to a colleague.
One of my LGs, is model number-
LG be12lu38 I think the other one is slightly newer. They have eSATA and USB.
From my experience with those three BD Burners on a Mac Pro and a MBP, its simple plug and play, hot-plugable, no hassle. If I recall correctly, the LGs burn significantly faster than the LaCie did.
The Matrox MAX thing is a hardware device that works with Compressor to encode H.264 files much faster. It comes with presets for Compressor. There is a less expensive option, Elgato turbo, but I have no experience with it. If you won't be doing a lot of long form h.264 stuff, probably neither are even necessary.
My suggested workflow would be to Export a Master File from FCPX, then bring that into Compressor and apply the Apple Blu-ray audio and video preset settings, in the Disc Burning folder. Add the Job action "Create Blu-ray Disc". Be prepared to wait much longer than you might expect.
Shortly after my first Blu-ray burn with that workflow, a 2 hour project, I bought
Matrox MXO2 LE w/ MAX and never looked back.