Pros: Sturdy and pretty comfortable
Cons: Limited presets; too much bass for FPS use; sound not customizable; charge does not last 8-10 hours
If the A50s gave you the option to customize the presets, I imagine that they would be great for FPS gaming. However, they do not and even the preset with the least low end has too much to hear any of the subtler sounds (e.g., footsteps). I use them with a PS4 and have tried every possible combination of settings to no avail. There are far less expensive options on the market that offer more features with better sound for this use.
Professional gamers do not use these. If they use Astros at all, it will be the A40 with Mixamp pro. Some bigger COD Youtubers promote these because they have a sponsorship, but do not actually use them often.
Note, that when Astro released these and for a couple years after, they promised software that would allow for custom audio presets. They even said that it was in beta testing at one point. However, they never released anything and have made it clear that they will no do so. Rather, they have said that the third generation A50s will have something like that and I should consider "upgrading" upon release.