This is my second system in a row using Corsair Dominators, I'm very happy with them. I don't think most people need 8GB of RAM, I don't know if *I* even need 8GB, but I put together a new i7 system running a 64-bit OS, so what the heck. Besides, the blue and black goes very well with my MSI motherboard. :)
The RAM comes with a 2-fan cooler, my older DDR2 Dominators had a 3-fan cooler. I'm not sure what the big difference, you'd think that larger fans mean slower speed, but at this size, they're still running at 4000 rpm and can be pretty loud, but as long as your motherboard can be controlled with Speedfan, it's not a big deal. I have the fans running at 3000 rpm now and don't hear them.