I've had my first hands-on trial of the rMB today, and have to say that I was very impressed with its performance on the whole. I opened up: Logic Pro X Garage Band Photos Final Cut Pro X Preview Safari with several largish web pages ...and didn't notice any worrying delays. Logic Pro took a few "bounces" on the dock to open, but was pretty quick once it did. Scrubbing video in Final Cut Pro seemed smooth. Swiping between desktops, or going to Mission Control or LaunchPad were all good and quite smooth. I didn't really see any significant difference in responsiveness between the base 1.1GHz rMP and my late-2013 quad-core rMBP 15 with discrete graphics. A little bit slower, but not significantly so. It was about on par with my quad-core Mac Mini (2011 with HD3000), so perfectly usable. I have a family member with a new base iMac (1.4GHz with HDD), which feels quite sluggish in comparison to the rMB (probably due to the 5400rpm HDD). The only thing I did find slow was the preview function in Finder (hitting the space bar over subsequent files). Files that opened in Preview seemed to take a long time (several seconds) to render their view. The screen is great - 1440x900 seemed best for most things, and I quite liked the keyboard, although it would take a bit of adjustment to get used to the limited key travel. The light weight and overall tiny footprint is astonishing! I also had a chance to try out the Surface Pro 3 and new Surface 3 on the same day. I had looked at the Surface Pro 3 before and thought "meh", but I was actually quite impressed by the Surface 3 - even with only 2GB RAM. It was surprising responsive - about the same "feel" as the rMB. Maybe the quad-core Atom will be OK! The Surface 3 isn't as impressive or nicely designed as the rMB, and the keyboard and trackpad is awful in comparison (although usable), but it didn't strike me as a bad option for someone looking for an ultra-portable at half the price of the rMB.