Because so many closed loop cooler vendors have been basing their designs off the same basic products from Asetek and CoolIT (and inheriting the quality control problems from CoolIT in some cases), they've been forced to differentiate through features and fans. Corsair's "i" series coolers get to enjoy the Corsair Link ecosystem with sophisticated fan controls, while NZXT's Krakens have decent software-based fan controls of their own.
Swiftech changes things. Since they're already established in the liquid cooling market, the H220 is positioned less as a closed loop cooler to just be marketed to the public and more as an entry into the world of liquid cooling. Swiftech wanted to make the H220 as easy as humanly possible to install while offering enough of a performance reserve that if someone wanted to open the loop and start tinkering, they could. At CES, the H220's pump was demonstrated keeping a pair of GTX 680s and an i7 cool.
... the radiator itself has a larger reservoir than the competition, is user accessible and serviceable, and is produced from higher quality materials. Instead of just using aluminum, the H220 has copper fins and brass tubing, which theoretically will allow it to both dissipate heat more effectively and last longer. That also means it's much heavier in the hand; when you hold the radiator you can feel the difference in a big way. (Source