My Pegasus2 has just been replaced by Promise RMA.
It still doesn't work.
On my Mac Book Pro 2010 it's not bootable and not detectable during boot. But otherwise, after booting it mounts on the Finder's Desktop and it is recognised by the Promise Utility.
But on my Late 2013 Mac Pro, since the SMC Update 2.0, it's only listed in the SystemProfiler. It's not detected by the Promise Utility and not mounted on the Finder's Desktop, and of course it's not bootable or detectable during boot.
Please Apple, do something for us, big users of the new Thunderbolt utilities.