Unsurprisingly, battery life isn't great, but the large 90Wh battery does still help. In fact, it managed to edge out the Lenovo Legion Y740 in PCMark 10 Modern Office, albeit with NVIDIA Optimus enabled, which means that it was probably running off the integrated GPU at some points.
The Gaming numbers were obtained in Discrete Graphics mode though, and the laptop lasted barely over an hour.
The Mothership didn't fare well in our portability index either, which takes into account things like weight, dimensions, and battery life. Given how large and unwieldy it is, it ended up right at the bottom of the chart. Suffice to say, the Mothership isn't very portable at all, despite adopting a form factor traditionally associated with mobility.
Cooling is another area where the Mothership shines. The entire keyboard remains cool to touch while gaming, thanks to the fact that the CPU and GPU are no longer located beneath the keys. I measured the surface temperatures after running 40 loops of 3DMark Fire Strike Extreme, and as you can see, they're significantly lower than most of the other laptops. CPU and GPU temperatures are pretty good as well, so ASUS' unconventional design has at least paid off in this area.
The Mothership does get noisy under load, but it's still in line with most of the other gaming laptops today.