So I have a late 2012 iMac. 21" 2.7 i5 with 16 gig of RAM. The thing has become dirt slow. I am sure some of it has to do with the hard drive as its a 1 gig drive that is about 95% full. I just got an external HD and I am moving files to that which should clear up over 1/2 the hd. I will see if that helps. I do a lot of web development (html, css coding). I develop websites as a consultant. So I also use a few graphics and other development tools. I also do a lot of iMovie editing. I am thinking about getting a new iMac. Would the most important feature be a fusion drive? I was thinking of cheapest 27" with 2gig fusion. Or 21" with 2 gig fusion. Would that combo bring me a better speed increase than going for a higher processor? Trying to keep cost down as these things are way expensive. But when i spend more time sitting watching a spinning color wheel than coding its costing me time and money.