When it comes down to gi vs no gi training/competition... people seem very polarized in opinion. Marcelo Garcia says that to get good at no gi, you must master the gi. Eddie Bravo on the other hand would say the exact opposite.
In my opinion, a large amount of techniques are actually shared between the two. And since both are pretty important parts of BJJ, training should be divided roughly 50/50 % between the two.
I feel that in no gi, the skill disparity between two people is not as evident as with the gi on, simply because of the amount of available moves that are taken away.
Now here is the "classic sweep" or "shaolin sweep" done by world champion Robson Moura