I measured the external temperatures of the four quadrants of the notebook after 40 loops of 3DMark's Fire Strike Extreme stress test. This amount of time is more than enough to get an idea of your average maximum running temperature for this workload.
One good thing about the MSI laptop is how cool the palm rests remain even when the laptop is working hard. Instead, most of the heat is concentrated in the area above the keyboard.
I used the built-in battery life benchmark in PCMark 8 Home to assess the battery life on the laptops.
The good-sized 82Wh battery on the MSI GS65 Stealth Thin means you won't have to hunt for a power outlet the moment you unplug your laptop. It's not quite up to par with the Gigabyte Aero 15X and its larger battery pack, but it's still a good showing nonetheless.
The portability index is an objective measure of how portable a notebook is, taking into account factors like size, weight, and battery life.
The Gigabyte Aero 15X was the clear winner here, thanks to its unparalleled battery life. That said, the MSI laptop didn't fare that badly either, coming in just a hair behind the Razer Blade.