When researching which iMac to purchase, I had trouble finding some solid real world comparisons regarding the performance of the iMac i7. So thought I'd share my experience with it so far. I received my refurbished iMac yesterday. I'm coming from an early 2008 15" MBP, 2.5ghz C2D, 4GB RAM, 512MB VRAM. So that is my base for comparison. I use my computers primarily for photo editing using LR, Bridge and Photoshop. I do not play games on my computer and seldom edit videos. I purchased the i7 for the screen, multitasking ability as well as speed. Screen When I first turned this thing on, I couldn't help but laugh. This thing is so massive compared to my 15" MBP. It's seriously a beauty. Now I had concerns about calibration due to the glossy, high contrast screen. I've calibrated my monitor and compared it to my very accurate MBP screen and both seem to be similar for color. So I'm expecting my photos from the lab to come out just as great as before. Additionally, due to its size and resolution, I am seeing detail in my photographs that I've never seen before. This advantage over my MBP is invaluable to me. Upgrading to a larger monitor was long overdue for me. Obviously I was also concerned with all of the reports of yellowing, flickering, light bleeding, etc. I'm happy to report that my screen has no dead pixels, no flickering (so far) and no noticeable yellowing. The yellow tinge was a huge concern for me (especially because it's a refurb). I rely a lot on color accuracy as part of being a photographer. I think it may possibly be very slightly warmer on the lower half of the screen, but it's really hard to say. Definitely wouldn't have noticed anything if I wasn't looking for it. There is an ever so slight backlight bleed in the very bottom right corner. This is only noticeable on a completely black screen and does not affect my work. Performance Before deciding on the i7, I viewed a ton of benchmark scores comparing the different iMacs. I also watched all the youtube videos I could find showing off the speed of the 27" iMacs. I also played with two iMacs at the Apple store (3.06 C2D and i7). I had a lot of trouble seeing any real world speed increases between the two. But everything I read kept saying that the i7 was a beast and dominated the lineup in regards to performance. So of course I became excited about having the best and went the refurbed route to afford the i7. What I've found in my real world testing is that it's not a gigantic leap in speed over my 2.5ghz C2D MBP. It is faster, but not as much as I originally thought it might be. I was extremely curious to run some of my more intense photoshop actions on the i7 to see how long it took in comparison to my MBP. Time savings in this regard would be absolutely huge for me, as it means I could process sessions faster and potentially take on more shoots as a result. To be honest, at first I was a little disappointed that the actions didn't run a little faster. One of my actions in particular incorporates a lens blur filter and it takes forever on my MBP. It still takes some time on the i7, but... I did some side by side comparisons by running the same exact actions on the same exact photos (from 5D Mk II, btw). As a control, I did a fresh restart and opened Bridge & PS only on both machines. And it turns out my actions are running faster on the i7. One action took 1:53 on the MBP, while 1:27 on the i7. This isn't as huge of a leap as what I was hoping. However, the advantages of the i7 lie more within what you can do while running the action. On my MBP, while running the action, I can't seem to do a whole lot else without severe speed reductions in Photoshop. I didn't time anything, but I can tell you that the time it takes to run that same action while navigating in other applications on the MBP probably doubles. The action almost seems to stall sometimes. The computer just can't keep up with the challenge of multitasking. And here's the genius of the i7. While running the same action on the i7, I can jump all over the place. I watched The Office on Netflix, opened up LR, played in iTunes, etc. all while the action was running. No slowdown whatsoever. This is exciting. And also why I feel the i7 was totally worth it. Multitasking is such a huge thing for me. Screen and performance were the two reasons I purchased the iMac i7. And in my short time with it, it failed to disappoint on both fronts. Here's a pic of what I'd probably call my favorite purchase of all time, with the iPhone 4 in a close second.