Based on the US-122L, the US-144 adds an S/PDIF digital I/O to the two XLR mic inputs. Like the US-122L, the US-144 includes 2 line inputs, one of which is switchable to hi-z for use with guitars, basses, etc. Supporting USB 2.0, the US-144 offers low latency and support for 24 bit, 96kHz high quality audio. RCA connectors provide line level output. A MIDI input/output is available for connecting a MIDI keyboard or other device, and the US-122L is self-powered via USB, making it perfect for laptop users.
To assist in hardware monitoring, the US-122L includes a headphone jack with level control. Of course, if you need more than 2 inputs, the US-122L isn't for you; otherwise, it is an excellent value.