Build Quality:

The Cooler Master Masterkeys M is an extremely sturdy keyboard. Made of strongly enforced plastic, like its predecessor the Quickfire Tk which we have reviewed before, the keyboard is hard to flex when put through our stress test.
The housing of the cooler master Masterkeys M is also very sturdy, made with 2 metal plates inside the keyboard, 1 below the circuit board and 1 between the keyswitches and the circuit board, giving the keyboard once again a very rigid feeling whilest at the same time, preventing any keyswitches from being damaged if too much force is exerted on it. The keyboard held its structural shape and none of the keys stopped working when we conducted the drop test on the Masterkeys M. Making the Masterkeys M a very good keyboard in terms of its structural integrity.

Backlighting:

The backlighting of the Masterkeys M exceeded our expectations, producing a vibrant and bright white backlight.
This is most likely due to its white coloured backplate, which helps the Masterkeys M reflect any light which hits it, back into the keycaps, providing the user with some of the best single coloured backlighting in the market currently.
There are many backlighting modes with the masterkeys m, which can be toggled through the fn keys + the F1 to F4 keys. Firstly, there is a static mode, where the white backlighting remains at one brightness level, adjustable by the user.
The second mode available to users is the breathing mode, where the keyboard cycles through all brightness levels, going from its dimmest setting slowly up to its brightness and slowly dimming again where the cycle starts over.
Another mode that comes with the keyboard is wave mode, where the white backlighting starts from the left and slowly moves towards the right, before restarting from the left again. Another variation is split wave mode, where the wave starts from the center and moves towards both left and right sides. Overall, the masterkeys M has some of the best single colour backlighting and backlighting modes possible. Although many keyboards these days have RGB addressable backlight, the masterkeys shows that even though it is a single LED keyboard, it can still stand up to the other higher end keyboards in the market as a contender.

Keyswitches

For keyswitches, the Cooler Master masterkeys M comes in 4 keyswitches. They are the cherry MX reds, blues, browns and greens, with each switch having its actuation force and bottom out distance. For example, red switch models have a 45g actuation force and a 2mm key travel, with 4mm to bottom out with a linear feel. The blue switches have a 50g actuation force, a 2mm actuation distance and a tactile feel, giving a clicky sound a feel when actuated while the brown switches have the 45g actuation force of the reds and the tactile bumb of the blues.
The keyswitches themselves however are still the best part of what makes this keyboard good, using Official Cherry Switches on a keyboard at the price range is rarely done, but cooler master has done it and has done it well. Our model, coming in with Cherry MX Red switches, has a 45g actuation force, while being a linear switch for commands being executed fast and swift.
The keyswitches feel good to the touch, no key wobble is present when the key is pressed and long term usage doesn't cause fatigue to the user. However, the only problem with the keys is that the keys themselves may sometimes actuate when little pressure is applied, which is a fatal flaw for many red switches out currently as pressing 2 keys when trying to press 1 occurs in many cases.

Final Thoughts:

Overall, the Masterkeys M from cooler master gets a 8/10 from us. For the price you can get this keyboard for now, it offers some of the best functionality which can even compete with high-end keyboard from corsair or even Razer.
The Cherry MX switches on the keyboard also provide some of the best feedback out of all the switches we have used before and unlike some knockoff switches typically found in this price range, doesn't cause any fatigue after using it for long.
The keyboard is also sturdy, with metal plates and a hard plastic shell not allowing for any flex on the plastic shell and the 2 metal backplate not allowing for any switch movement when the keyboard is being used or flexed.
I really recommend this keyboard for users who want all the functionalities of a normal keyboard, minus the RGB lighting and who want it in a good chasis with good switches.