Same with me. Before upgrading I always used to close the lid to make my macbook to sleep. The wake-up experience was good. But after upgrading, after waking up the system becomes too slow to use. I have to restart. So stopped putting my mac book pro to sleep. Now I always have to shut down when not using. Apart from sleep-wakeup problem, in general this has become much slower compared to mavericks

Probably this could be related to hardware config. I have a mac book pro at work with 8GB ram and it works fine. My personal mac book pro has 4GB ram and it has problem.