Stability has substantially increased with using the 64-bit client and I have personally faced zero issues with using this.
Though most of our servers do not make use of Chromium, it is generally useful to keep in case we ever introduce a feature that may allow you to play YouTube videos in-game, for example. Right click GMOD in the steam app > Go to properties > Go to Betas > Open Drop down menu > choose chromium. A few years ago, 64-bit Garry's Mod was released and it can allow not only a increase in performance but it will also introduce Chromium as part of it. When you download Garry's Mod, it will use the stable branch which is 32-bit.
