-Volume control has no native support to set routing for I/O channels,
-Experiencing some lower record levels compared to win(I still need to check for sample-rates o.e that causes this)
-Qt Sixisix Mixer(for this 6i6 device only) has some issue with the Mint 18.3 Alsa, expecting better results with Ubuntu 18.04 based Mint19.x
"This is a bug in alsa, not a bug in qsismix. The controls that qsismix uses to interact with the 6i6 hardware should be listed under amixer controls, but for some unknown reason are not available under some system configurations. A possible work-around is to disable pulseaudio when you want to use alsa's mixer controls, although I am not sure that pulseaudio is always the culprit and pulse runs along with alsa on my system without issue."