It definitely gives nausea and dizziness in excessive doses, just like alcohol and benzos (I assume most GABAergics in excess will cause this). To me (my max single dose is 4g), it never gave a sense of euphoria, certainly nothing like opiates or even the buzz I could sometimes get (albeit rarely) from short acting benzos like Xanax. Stimulation and sedation would cancel each other out, which one dominated when you took it? I found it didn't noticeably cause either for me.