Steinberg's UR22 MK2 is the updated version of their original USB interface which features the well thought of Yamaha D-Pre preamps that come as a result of the joining of the two companies - Yamaha owns Steinberg, in case you didn't know.
So, whats new? Well it's all in the power options. The UR22 MK2 adds a separate 5V micro USB connection to allow use with iOS devices - as it's class compliant, the UR22 MK2 works out of the box at up to 192kHz 24 bit. Unfortunately this doesn't extend to charging the iPad while hooked up this way.
Also a nice inclusion is the MIDI i/o on proper 5-pin connections. It's a simple setup, two in on Neutrik Combi jacks, input 2 switchable to hi-z for instrument input, both with 48V phantom so you can drive the full range of mics. Though you will need a decent ampage on if using with the external power supply. There's the usual Direct/Return fader for zero latency monitoring, which makes it work for solo recording - though monitoring is only mono, even if you use a stereo source.
In this review Gaz put it through it's paces on alongside Cubasis on the iPad (an iPad Air) by embarking on a full recording session. The track is called Killer Company and uses 24 tracks at 44.1 16 bit. A variety of sources - DI from bass, and a mixture of condenser, dynamic and ribbon mics.
The Steinberg UR22 MK2 is available now, it's not the lowest cost interface, but you do get the D-Pre mic amps and a solid, class compliant unit which stood the rigours of this test.