I will be surprised if we see another driver update for the US-NxN interfaces. I hope for those owners that they got the issues with the US-20x20 worked out. Time to start saving for an RME i/f.
Even if I switch to S1 for all work instead of some, I don't trust PreSonus to support their hardware for any length of time even close to the life of the product. Got a Studio 192? Got a problem? Too bad, the Quantum is out now. Oh crapola, the Quantum 2 was just announced/released. Better not have a problem with your new (now old) Quantum. So, the 'tight' integration with S1 doesn't mean doodly squat to me.