The 3rd Gen comes bundled with better software than the 2nd Gen, and has a better built-in pre-amp for mic recording, however, the 2nd Gen is better overall. One of the main benefits of the 2nd Gen is that it is both bus-powered and mains powered, meaning you can use it on the go, and also plug it in when at a workstation. This is beneficial, because more power, means your interface is less likely to overload and cause problems during recording. Furthermore, on the 2nd gen, you get a separate headphone volume control, which is (in our opinion) a massive bonus over the 3rd Gen.