I am proclaiming a reliability level for El Cap as "Useable". This has been granted when the most active threads here discuss items such as scroll direction and the default system font. (this rating is backed up by my production machines being very stable) Thank goodness as it has been pretty rocky getting here. In the next few months the cycle will start over again with 10.12. I hope the folks involved in Apple have learned something from the 10.10 and 10.11 development cycles.