OCModShop posted a review on the Enermax Twister Case Fans

There are numerous options out there for cooling your case. The last I checked everyone and their mother had a fan that was meant to optimize the effective cooling by having different blade shapes, or floating magnetic movement opposed to ball bearing movement. And then there are sizes... LOTS of sizes. Everyone's fan is better than anyone else's, and the world of cooling has been revolutionized by simply changing the shape of a plastic blade and punching a few holes here and there. Kind of makes you wonder what, if anything, is changed about such minor alterations.

The thing is, that as minor as these changes are to those who don't design fans for a living, simply changing the shape of the blades could easily add much more airflow, reducing the need for the blades to spin faster, thus creating a quieter PC for us all. That's what Enermax did. They got their brilliant monstrous brains together and came up with a fan that could keep our cases cold while providing much less noise in the mix. They called it the Twister, which I thought was a silly name for a fan. But you know, who cares if their naming skills suck? They designed one hell of a cool fan. Here are some details on it:

Enermax Twister Case Fans Review