I have a MBP with Core Duo still running Mountain Lion, I´ll update in the following weeks (I like the look of this OSX version), have another mac in the office, a Mac Mini late 2013 with i7 that machine runs the latest OSX (10.10.4) and finally have a Hackintosh (Quad-Core 2.4 and runs Mavericks) by the way runs wonderful
I need to install in my hackintosh one of the latest Otter versions to test in this machine, I have the Otter in my office.