I have a Motu Track 16, and had a few disconnections at first (and some annoying issues when the Mac went in sleep mode, and also to sync the Motu to an external wordclock).
But since I uninstalled the Motu drivers, it's working perfectly. No disconnections, no drop-outs, and very stable.
Setup:
Pacarana connected to a Mac Pro.
Motu track 16 connected directly to the Pacarana via FW.
Motu track 16 connected via ADAT to RME RayDat (also receiving clock from the RME). 8 ins, 8 outs.