I have a 2014 15 inch rMBP and it's my favorite computer of all time, no doubt. I'm a developer by trade and I use this machine as my main driver. I keep finding myself drawn toward the 12 inch MacBook because on top of traveling all the time, I also cycle to commute probably 80% of the time and I prefer using a backpack to transport stuff. My standard commute is about 25 miles round-trip and every pound really does count (and after feeling the MacBook myself it's unbelievable what the difference in weight feels like, even if it's only a few pounds). I have an iPad that I use for mobile consumption when I'm not going to do any work and I feel like the MB will unify these worlds. The 15 inch also has a very large footprint compared to the 12 inch, and it eats up most of the room in my pack. I've also learned that this 15 inch rMBP is probably more power than I need. I can't think of anything I do now (or will be doing in the foreseeable future) that requires very much power as most of my work is developing simple LOB apps. The only issue I can see here is that I use Parallel's into a Windows VM for .NET development fairly often (using Visual Studio 2015) and I'm not sure how well this machine would handle it, though I imagine it would be fine. I don't want to have two laptops as I know I will tend to always gravitate toward one, so if I decide to go this route I will be selling my current 15 inch rMBP. The biggest downsides for me are that going from 15 inches to 12 inches will be difficult because even though I really love super portability I also love having good screen real estate. I can somewhat makeup for this by scaling to a higher resolution and having about the same desktop space, though smaller. Also, after messing with the keyboard it seems like it would be hard to get used to for longer work sessions, though my experience is so limited that I don't know if this is an issue long term. Also, I'm not sure how fluid everything will be compared to my current machine. I don't mind that the 12 inch is (far more) underpowered than my current rig if it handles my usage patters just fine, but I don't know if the MacBook is up to handling a VM into Windows, Visual Studio running, etc and remain smooth. Any developers out there use this as their main machine? How is it working for you? If you've moved from a larger laptop like the 15 inch to the MB did you find that you regretted your decision in the long run? Any help is much appreciated!