Whats the deal with dosages?

So many of you say take at least 100mg. However a lot of pills seem to contain around 60mg (give or take). Does that mean that you'd need to take 2 of those pills or do you guys just like higher amounts. Many people claim that anything less than 80mg is useless but I've don't 70mg and felt great and extremely couch locked. Is there something I'm missing with pill dosages vs a powder?