[Dazarath]

OP, you're dead wrong. If you play an 18/13 style at full-ring, would you play 18/13 at 6-max? What about HU? The optimal style at 6-max is necessarily looser than at full-ring. What happens a lot of the time, though, is that players over-adjust and become too loose, or too aggressive.

SixForty, if you ignore bunching, then 6-max is the same as full-ring with the first four players folding, at least in terms of game structure. Where it differs, though, is that the table texture is so much more aggressive. Full-ring players tend to be much nittier than 6-max players, so when you get popped on the turn, hands like top pair don't look so good anymore. But in 6-max, the range of hands that players will pop you on the turn with is so wide, that you should be 3-betting top pair for value a lot of the time.