If you do the minor mods mentioned in the Rocketfish threads, then the Rocketfish can be made pretty quiet even with the stock fans (which push nearly 50% more air than the stock fans of the 690). You can install a fan controller for even quieter. But I was surprised at the low noise of the 690 considering how porous it is. I think it will be a bit harder to manage the air flow in the 690 as it has so much superfluous venting. The RFFT has a good amount of superfluous venting too, but not nearly as much. I think the 690 ia a better cooling case OOB, but the RFFT can be made into a very good cooler with a bit of thought and tweaking.
BTW, the 690 looks like a compact box standing next to the RFFT...
.bh.