Personally I am a spreader. Guitar picks work well in a pinch. I have also had good results with the MX4.
You have some good fans. I use AP14's and AP15's on my rig. Honestly fans (1850 RPM/ 2000 RPM / 58-60 CFM) won't make a huge difference in temps unless you go to some really noisy deltas or something like the BG Blasters (100+ CFM).
I'm a fan of big and slow. Big rads and slow quiet fans with high static pressure. Your limiter right now is most likely the H70. If you want to stick with that setup, You might need to invest in some bigger CFM fans if you want much better temps.
If you want to keep your rig quiet, I'd stick with the GTs and look at another rad.

PS: Intake will get you better temps than exhaust in all my testing. You want the coolest air possible hitting the rad.
Edited by pgdeaner - 11/8/12 at 10:11am