I had to roll back to Yosemite some months ago in my MBA (2014) since after updating my external audio card (Roland OCTA CAPTURE) stopped working after 5-10 minutes, and had to reconnect it again or sometimes reset my Mac to make it work again. At first I thought it was Roland's drivers bug, but every drivers they released for that audio card were rock solid (from Mountain Lion to Yosemite, 0 problems with many hours a day of usage). Then I read somewhere it was El Capitan problem with USB 3.0 external devices/hubs, making them disconnect frequently, but it was also supposed to be fixed on 10.11.4. So my question would be: are there still external USB 3.0 problems with the now 10.11.5? I haven't tried it out since I have to work with this machine and can't be losing time updating and rolling back, but if some of you guys use external audio cards with El Capitan, I'd be glad to hear how are these working for you.