Arguably, I think you could say that the 2-4 variance is higher than 1-2 NL. It's true that in 2-4 you aren't going to lose $200 in one hand, but you can easily lost large chunks chasing draws, etc.

While one can easily lose $200 in NL on a bad beat (ex. AA getting cracked by KK or something like that), I think you have more control over your wins/losses. You definitely play less straight/flush draws that might cost you money. I've played 1-2 NL several times with a $200 buy in, and my friend has as well (he usually buys in for $150), and neither of us have ever gone broke in one playing session. Granted, my times in a brick & mortar casino is a small sample size. I just think if you are a tight player, that there is less variance in 1-2 NL than 2-4.