No problems on the 5K iMac I use at work. Most people around my office are on 10.11x too and I've not heard a whimper or whine about El Capitan for months. But, yea, I agree with GS: most folks come to this forum to solve a problem or complain and not to write about how great an OS is. if the OS works well they're busy working and living life and won't waste time visiting forums to say all is well...