Dave has phenibut called GABAWave, you want to start here
That link above explains phenibut, Its main benefit is that help calms you down, since it is able to cross the blood brain barrier. I dont follow how something is supposed to calm you down, helps improve intelligence/focus/attention. So far, nobody that I know personally benefited from Pheniput when it comes to that.
Since it helps calm you down, you can have better sleep.