I agree with Nate. There is something to it, but it takes work to get it right. Some try it and it sucks so they say sub-ohming doesn't give you anything, but it takes time to get it right. It's not for everyone, most people don't want to fiddle that much. Some also don't care for the density or heat produced. Sub ohmers are like hot rodders. They fix up their cars and spend lots of money and time to make it perfect. Then they (hopefully) drive 35 mph on the city streets. Get 'em ona track and watch out!
Some of the things they learn may be implemented in future production automobiles to improve performance, everybody wins.
I sub ohm, but my all day is a 1.9 ohm Russian 91%. My mech is just for cloud chasing fun, which I don't even do on a daily basis.