I've been reading through the forums here for weeks and it seems like a high number of people have returned their iMac 5K with Retina. Just wanted to start a thread asking...why? I'll tell you my story. Have: 27-inch Late 2012 iMac, 3.4GHz i7, 32GB RAM, NVIDIA GTX 680MX 2GB Got: Base model iMac 5K Retina, 3.5GHz i5, 8GB RAM, AMD M290X 2GB I upgrade I would say every 2-3 years. My current 2012 iMac runs great, fast, quiet, plays games, can handle anything I throw at it including video and audio production and photo work. I play games on occasion but not often. Seeing the Apple keynote I was immediately interested by the 5K screen, I decided to see it in person at the Apple store. It looked great. I went online because I wanted to order the top model, i7 with AMD GPU 4GB. It says 2-3 weeks, but if you go all the way through to the checkout, the last step before confirming, it gives you are pretty exact ship date. It was almost a month. Plus for some odd reason, the ship to store option was an extra 3-4 days. I did not know if I could wait a whole month. I decided, maybe the base model would be pretty comparable to my current model. I could walk into the Apple store and buy it that day, which is what I did. Unboxing and plugging it in, the first thing I noticed was the fan sound. I am in a pretty quiet room, and I guess I did not really think about how quiet my 2012 unit was. Now the sound was not loud, and the fan was not "spinning up", but the normal fan sound was audible. Very light and not a huge distraction, but noticeable. The screen looked awesome. Text was nice and sharp. I tried doing some web browsing, going to sites I would typically visit. After some basic use over the next hour, I noticed the 5k did not seem as smooth, with web browsing, popping up a finder, using mission control. Just slight millisecond pauses here and there, granted I was trying to torture test it, but I was expecting it to be more like my 2012 but only faster. I feel like my 2012 is like butter, with everything, but the 5K just seemed a little pause-y here and there. It was enough to be distracting. I did not even get into games or anything too demanding, I was forming an opinion already. I always get a new mac and am wowed by the performance. I assumed the older mac and new one would be pretty close in performance. But it did not seem to be. Other than that, the screen looked great, but I did notice non-retina graphics more on websites. The Apple website, especially the Apple Watch pages, looked almost 3D. But surfing away from that was more a mixed bag. The only other thing I played was 4K videos. They looked fine, but I often found expanding them or exiting them also produced little micro-pauses. I realize there are a lot of pixels moving around, but it was not something I was expecting. Not in 2014 with Apple's top of the line iMac. I boxed up the iMac and returned it after a day. I should have spent more time with it, but the initial impression just rubbed me the wrong way. Maybe the next few software updates will fix it. Or maybe I should have added more RAM like I planned. Or I should have waited the month for the top model to ship to me. All in all I was disappointed. I will wait until the 2015 retina iMac comes out. I hope they get the screen tuned to perfection, maybe switching to NVIDIA. Or something. So that's my story..what's yours?