I've had a mid-2011 21" iMac for a few years now which has been great but I need a bigger screen mainly because I do some web design and could do with the extra space. I've been looking at the 27" non-retina models because the retina model is out of my price range. I've noticed that although the retina model is new the others haven't been refreshed for a while. Does anyone know if a refresh is due anytime soon? Not sure if I should buy or wait. Thanks in advance.