The GT72S 6QF Dominator Pro 4K is a massive slab of plastic that, practically speaking, is more like a desktop computer than a portable notebook.

At close to 4kg, this MSI gaming tool is what the industry calls a desktop-replacement laptop.

It even has an actual desktop-class Nvidia GeForce GTX 980 graphics chip that lets it run the latest games at maximum settings, like rivals Asus ROG GX700 and Aftershock Titan.

While its Intel Core i7-6820HK processor remains a notebook-class model, it is one that caters to enthusiasts. For instance, it can be overclocked to run at a higher frequency for a slight performance boost.

But in system benchmarks, the GT72S is slower than the Aftershock Titan, which has a proper desktop-class CPU. In the PCMark 8 Home test suite, which runs apps typically used by home users, the GT72S scored 3,492 compared to 4,936 for the Titan.

The impact of the Titan's desktop CPU is less pronounced in gaming. In Crysis 3, the GT72S produced around 67 frames per second (fps) at the maximum graphics settings and at a screen resolution of 1,920 x 1,080 pixels, compared to the Titan's 71fps.

The GT72S has a 4K (3,840 x 2,160-pixel) screen. But even with its desktop-grade graphics prowess, it will not run Crysis 3 smoothly at the maximum settings at this ultra-high resolution. I had to lower the settings by a notch to achieve a tolerable 31fps. However, not all games are as graphically demanding as Crysis 3, so 4K gaming is definitely viable.

Because of its thick chassis, I found it uncomfortable to type on this laptop. But this can be alleviated with a palm rest.

The keyboard, designed by peripheral maker SteelSeries, has good key travel. Like many gaming laptops, the keyboard backlight can be customised to your preferred colour.

The Windows logo key has been shifted from the left of the space bar to the right, to prevent gamers from accidentally pressing it and having their gaming session disrupted.

You can also disable this key via MSI's Dragon Gaming Centre app. This utility shows key information such as temperatures of the CPU and graphics chip, and lets you adjust the speed of the internal cooling fans.

Left of the keyboard is a row of shortcut buttons allowing you to quickly execute tasks, such as launch the XSplit live streaming and recording app for games, increase the fan speed, and switch between the powerful Nvidia graphics chip and the integrated, low-power Intel graphics chip.

For those looking to squeeze even more performance from the GT72S, the preloaded MSI Afterburner and Intel Extreme Tuning Utility can be used to easily overclock the laptop.

The GT72S is more expensive than the Aftershock Titan ($4,489), but the MSI laptop does have twice the amount of RAM, a higher-resolution display and a faster solid-state drive. On the other hand, the Titan has the better CPU. Pick the Titan if you value performance and customisation options, but I preferred the GT72S' keyboard and its software tools are better for hardware tweaking.

• Verdict: A gaming laptop heavyweight that will match most desktop PCs, at almost twice the price.