I have a Phenom II X6 1075T also and just got the Coolermaster Hyper 212 Plus at Frys.com. My old temps were 34C idle, 46C under load. Now it's running at 22C idle and 40C under load. Also, it is super quiet! The Hyper 212 is just $24 right now. I also used some Arctic Silver 5 thermal paste instead of the stock paste it came with.
The stock heatsink needs a good wiggling from side to side to get it off the CPU, as the stock paste is stuck on really good. When I tried to get mine off, I unintentionally pulled both CPU and heatsink off the motherboard. Luckily, none of the pins got bent. Just be aware of this!
I would also make sure that your heatsink is secured tight. 71C seems way too high, as I've read that max safe temp for Phenom II is 62C under load.
I don't know if 'not very efficient at all' is correct. It definitely dropped my temps and I'm pretty satisfied, considering I only paid $24 for it. Of course if I was an extreme overclocker, I would've gotten the Corsair H50 or better, but I'm far from it.
I just looked up the article from Xbitlabs.com comparing it with Hyper N620 and Cogage TRUE Spirit. I can only say that their data would be insufficient because they applied the thermal paste wrong. It's univerally known that heat is better transferred off the cpu with maximum surface contact between the seat of the heatsink and the face of the cpu. Observing the picture taken off their site: http://www.xbitlabs.com/misc/picture/?src=/images/coole... you can clearly see that they didn't even bother applying thermal paste in the gaps between the heatpipes which OF COURSE would make it inefficient.
I did some research before getting my hands into the installation and found this method actually makes the heatsink efficient.
Read this page and you won't be sorry you purchased the Hyper 212 plus: http://benchmarkreviews.com/index.php?option=com_conten...
Notice how the person filled the gaps between the heatpipes using the credit card method. Also, I chose the last method of putting tiny strips between the pipes...except instead of 2 strips, you're going to be using 3 strips since there are more pipes than the shown picture.
I hope this info is some help and good luck with the temps!