A really solid well made piece of kit. I bought this to replace my Motu 4Pre which although is also solid and has excellent sound, is difficult to physically control. Plus, I'm not a fan of virtual mixing boards. So it was a real pleasure to have tactile controls that feel good to operate. Used for speech and mixing/editing pre-recorded radio pieces it also allows me to attach 3 mics and a broadcast headset for live links to the broadcast studio via a Comrex BRIC-Link. The USB is connected to a MacBook Pro running Mavericks 10.9.4 and worked first time with no subsequent problems. Since gain on mics, for my purpose, is 'fix and forget', the need for sliders, and therefore a larger unit, proved unnecessary. There is also enough amp gain to cleanly power 'cold' mics like an EV20 and SM57 etc. Perfect for people like me who are not sound engineers and want an unobtrusive, intuative mixer on their desks. At the price, it's extremely good value for money.
UPDATE APRIL 2015: Now running on OS x Yosemite v10.10.3 with no problems encountered.