Looking at the review here:
The Komplete Audio 1/2 has an headphone output impedance of 10.21 Ohms, pretty high compared to the 0.06 Ohms of the MOTU M2 and the 0.35 Ohms of the focusrite 2i2/solo Gen 3.
The focusrite
has problems in the headphone out with low impedance headphones, but fairs okay at 300 Ohm outputs. But unfortunately has terrible crosstalk on the headphone out (-40dB ?!). The Komplete has no crosstalk issues, but THD+N measures slightly worse than the focusrite @ 300 Ohms.
Given the choice of these three I would probably just go with the Motu M2.
Wish we had DAC out comparisons for all these interfaces, and not just DAC+headphone amp out.