Did I miss something? Why is everyone talking about the Black Ice GTX? That's not one of the options the OP listed. The BI SR1
is the Black Ice model he's considering, which is a very different beast from the GTX.
Anyway, take a look at this graph from the Skinneelabs roundup
You can see the SR1 and RX both perform pretty similarly at low fan speeds. One other thing to note is the Thermochill PA performs almost as well at low airflow, and significantly better at higher airflow, so that might be something to consider if it's an option. The Swiftech MCR is also a solid option across all fan speeds, and, because it's a slimmer rad, it might allow you to run push-pull or shroud if you don't have the space for it with a thicker rad.
The Phobya G-Changer, per Skinnee's tests
, doesn't really compete with the other rads.
Ultimately if it's just between the three you listed, I'd probably go for the SR1.