What do you want to do with it?
If it is a range toy, then why worry about the speed of reloading or the speed of a second shot?
If you are using it for carry against large 4-legged threats, I'd lean toward the da/sa format, as you can get off a second or third shot while being rushed, or you can press the gun into the animal and keep pulling the trigger.
If it is SA then you would need both hands to cock and fire it for defense.
For the range, it is all a matter of how you want to shoot.
I personally like the look/feel of the SRH over the Redhawk and Blackhawk, but that is because I started with a GP100. The SRH looks like a big brother to it, so I am happy.
If I were to choose based on my favorite western star, I'd then go with an old time western look, and I'd pick a RedHawk. I personally am not interested in SA revolvers. I admit I'd only be using it at the range, so it isn't a real concern. I just like my revolver DA/SA.
That said, the Redhawk does look nice and feels good in my hands.
Oh, triggers? What they said. Too many variations from the factory for me to give meaningful input. Like was said, the SA can have a lighter [and safe] trigger pull than a DA/SA revolver, from what I recall. However, you can still have a crisp SA pull in a DA/SA revolver that is under 3lbs. That is good enough for me.