Best overall balance between performance/weight/battery life.
Best trackpad, hands down, no caveats, no balancing against other concerns. It's just that good.
Best integration with other devices (iphone, watch, etc). Making calls/sending text messages from a laptop is something I'm unwilling to give up at this point.
And most importantly, it's _by far_ the best support for a commercial unix/unix-like OS on a laptop. Dell isn't too bad though.
In the end, unix or a unix-like os is hard requirement for many of us, and I'm just too tired of fiddling with xorg/powertop to get decent battery life. I just want to get work done.