I don't know what kind of circles, but I guess driving retina screen is taxing the system. Still wouldn't give up my 2015 rMBP for an Air.
maybe not circles, but no UI lag is a big deal for me. I do not use it just as a "laptop" that much. I usually am docked to an external display. When I did that with the 2015 pro it was fine, but every time I would need to use it as a laptop the UI lag would drive me mad. I guess I just wish they had a full HD screen on a laptop. Imagine the pro with just a full HD screen. It would look great and perform like a pro. I was more shocked that the Air feels like it performs better than the pro. Granted, the benchmarks between the maxed out 13" Air and maxed out 13" Pro are pretty close.