I recently purchased the NN5 and it's definitely a beefy unit!

I have my Canon 40D with WFT-E3A wifi grip on it.

I just got my pneumatic air mast (for pole aerial photography) and did a few trial runs. I sent the mast up with a motorized pan/tilt head, with the NN5 and Canon40D/WFT-E3A on it, that's about 10lbs of gear.

At 49 feet (fully extended) it worked great, eventhough I did have guy wires on the mast and it was leaning over a few feet (that means even more force on the joints on the NN5)

It worked flawlessly!

Here are my test shots (shot 3 is full extension of 49 feet)

http://kmembrydesign.com/masttest.html

Kirk