@primaldivine
Mk4 is a very good solution because you have ADAT, so the possibility to ad 8 more channels easily.
Concerning Midi/Osc its not the same problem/solution.
With Midi IN/Out you can communicate with another musical devices, instruments, keyboard etc. but most of them are now directly pluggable in Usb, as nanoKontrol
Osc is more about the ability to change setting inside the audio-card from software or devices (touchOSC on iOs for example). RME have clear commands, easy to use. With Motu you can use proprietary modules, some in touchOsc to access some settings but its very difficult, perhaps impossible, to use OSC to change settings from Isadora.
You have to know that. RME Fireface UC is 875€, Motu ultraLite mK4 is 687€, for me with the difference in preamp and converter quality, the routing, the DSP and the OSC, if I have to choose now, its RME.