I bought a dual-slot Echo Express Pro for my two Universal Audio UAD-2 Quad PCIe cards [Tape Op #67, #76] and hooked it up to my Mac Mini (Mid 2011) with a Thunderbolt cable. I installed the drivers on OS X 10.8 (Mountain Lion), and the UAD plug-ins are working great in PreSonus Studio One Pro [#76]. I did not even need to reauthorize my paid plug-ins. (Authorizations are stored on the cards.) This is as plug-and- play as my computer audio life has ever been - no glitches with the UAD-2 cards in the Sonnet whatsoever, even with really large projects. Universal Audio has qualified both the single and dual-slot Sonnets, as well as the triple-slot ExpressBox 3T from Magma. I chose a Sonnet over Magma mostly because of Sonnet's 3 year warranty versus Magma's 1 year. You can extend the Magma warranty, but at that point, it becomes more expensive than daisy-chaining another single- slot Echo Express. The Sonnet's heavy aluminum case is sturdy, but the way it comes apart for card installation is a little awkward for me. And the worst thing about the Echo Express Pro is its fan noise - louder than my old G5's ever was. An ex- UA tech told me I can probably unplug the fans, as the UAD-2 cards do not get very hot (whereas UAD-1 cards could fry eggs), but I haven't gotten that brave yet.