I contacted the guy who owns dvnation. He's about an hour from me. We are discussing where I might pop in the car to head to his shop with a Mac Pro, Macbook Pro, to test how some of the different drives work.

There are a few 512Gb drives I want to try and they are rated as the fastest in the world. Honestly never expected to but recently did a setup in a location where I needed more than 128GB of HD footage.

I'll report back what I find but what I'm discovering is that there are plenty of bottlenecks that prevent playback before the SSD does. It seems that some of the cheaper solutions are doing just fine for Catalyst playback.