I'm totally impressed. Got my upgrade MacBook yesterday worked on it for about 3 hours, had 5 full screen desktops running 1-2 apps on each and this baby didn't skip a beat. Boot up and shut down in a flash. I've read about having to get used to the keyboard, but I haven't had that problem. I'm more getting used to a laptop this size having a full size keyboard. The Retina screen is awesome. You'd think something this thin and light might be flimsy, bot not this one. Picking it up with one hand and lid open, thumb on keyboard deck and 4 fingers under the case and no flex on the deck or case. Seems just as strong as my old Mac. This will surely replace my MacBook Air!