My wife has an X240, something in that series is equivalent to the Air. To be honest I would just go for the Apple, we have had quite a few problems with the Lenovo.
Ack. That's roughly where the CPU is, I wonder if some of the solder balls are cracking and it needs a reflow. I've never had to deal with Lenovo service, but it might be worth contacting them -- that is definitely a hardware issue.