For performance testing, I just replaced my Masterkeys Pro L that I normally use with the Masterkeys S PBT for about three weeks of daily use. This let me test it while gaming and writing. Considering all of the past experience I have had with the Masterkeys Pro and even the previous Cooler Master keyboards with the same exterior design most of my focus was really on the new keycaps. I kept a Masterkeys Pro out with ABS caps for comparison and just like I expected, the thicker PBT keycaps make a big difference in the feel and sound when typing. They give a more solid feel, especially if you bottom out the keys when typing. As for the sound, the green switches are obviously a loud switch but they have a different tone with these keycaps. Then of course in that time there was also no wear done to the caps, you would actually have to run them for a lot longer for any sort of comparison, but I have actually run PBT keycaps on most of my personal keyboards with no noticeable wear on any of them.
My other concern was with the laser etched legends, in the past, I have seen them be a little more vulnerable to dirt getting in and discoloring the legends but in my 3 weeks of testing this didn’t become an issue on the Masterkeys S PBT. The move to Costar stabilizers worked out decently. I didn’t have any rattling or issues with them when typing or gaming but as someone who will sometimes pull my keycaps off to clean my keyboard or to swap them out I would still prefer Cherry stabilizers so I can avoid fighting with the wires and tiny clips.
Beyond the keycaps, for anyone who hasn’t used any of the Cooler Master keyboards in the past. I was really happy with the thin bezel design, on top of already being a TKL keyboard they don’t waste any extra space with the bezel so the overall board is small and simple. The built-in function layer media keys are in an easier to use spot with them being in with the home button, you can use one hand to use them but I just never have any need for media keys. I use streaming for music most of the time when working and I don’t need to flip through any movies or TV shows.
Overall the keyboard has a good construction, you can't flex it at all and it is heavy enough to not slide around or anything. The plastic bezel does pick up some oils in your hands if you are handling it but it doesn’t rattle or move around. As for the new location of the status indicator LEDS, I almost never even noticed them. I rarely look at indicators anyhow but I would prefer to see them use smaller pinholes for the indicators to keep the look cleaner.