I use it. No side effects. Much higher level of focus. Any game jitters are almost non-existent.
As a consequence, I've brought home more money, plaques, and trophies in the 2 months since I started using it than pretty much my entire pool career combined. Not even kidding.
If it's not Cheqio calming my nerves and improving my focus to achieve these results, then I'll gladly accept the placebo effect.
I've only used it playing pool and absolutely do not feel any different. No crash. No letdown. Just results.