The article's conclusion about select() seems correct; however, after exploring select() performance in general, it then mentions epoll's exclusive flag in passing, and then dismisses it without actually doing any performance analysis.
And seems like both are quite different from IOCP too... kqueue_qos aside, you get the readiness state(s) and then do the operation(s) that look likely to be possible. So from this viewpoint epoll/kqueue/poll/select are actually basically the same - in contrast to the IOCP approach of doing the operation and then getting a notification when it completes. kqueue/epoll vs select/poll then looks like a more efficient way of doing the same stuff (with improvements - e.g., because the OS has more information to hand in the kqueue/epoll case it probably has more opportunity to minimize multiple wakeups, etc.).
Also, poll/epoll get even more versatile with current Linux systems, which take "everything is a file" much further with signalfd, timerfd, and eventfd.