It's really tall already, but if it could be wider, 120 or 140mm wide, you could use larger fans that have more CFM but less noise than a 92mm fan.

I don't like the bottom heatsink being in a different direction to the top. I'd rather it was running the same direction as the top one, then you could put a big fan on one end and blow air down both the heatsinks and put it in a tunnel. It looks a lot of hassle to manufacture the bottom heatsink, the way they made it, with lots of cut outs.

I'm sure Marto thought it was best to deliver 260GH, noise dB(A) wasn't mentioned in the purchase contract, but GH was!