I would say it is. As for OCing its fairly easy, you simply increase the speeds by 10MHz each time, then once it crashes you turn it down 10, and repeat for the memory. Once you reach the max you can increase the voltage to allow for even more speed, but that produces heat.
The fans themselves push more air, the heatsinks themselves vary as well. They also are on two different PCBs so each card is made different. Some dual fan cards, such as the ASUS Matrix are better than 3 fan coolers in some cases.