Currently I have Mavericks installed on my iMac and last weekend considered updating to Yosemite, but thought I might leave it a couple of weeks. While out shopping I was in a shop that sold Apple products so I thought I would have a quick look at Yosemite. My first impression was not good, firstly the close button in the windows did not look central, when clicking on a program sometimes it opened the right click menu and I was not convinced with the flatter look.
I did not spend much time looking at it, but the main change I did not like was spotlight, I could not move the dialog can could not get rid of the explanation of it. I looked at the possible settings, but could not find anything.
I have decided to wait until Apple sort these issues out, I did think what would Steve Jobs think about it, especially the off centre icon seeing how much of a perfectionist he was.