The difference is the airflow and noise, and the color, too

They're two completely different fans.
Smart Case Fan
Smart Case Fan 2
If you want an adjustable fan, get a
Y.S. Tech 
The main problem with the smart case fans, is the noise: they're simply not as quiet as they claim. Plus they draw excessive amounts of power, and I realy question their reliabity any more.
Thermaltake is basically eye candy, all of their products (with the
possible exception of their cases, but I thinkthey're ugly anyway

), and really don't perform as well as they claim.