All Exhaust V-band clamps not created equal?

[67XR7]

Mods please move if need be. Felt this was the best section for this question.

I'm looking into having headers built or building my own there seems to be a ton of V-band flange/clamp manufactures. During some internet searches I have found a lot of stories of leaky flanges when buying too cheap.

I found these

http://youtu.be/mCGXG0p6ij8

They are about $30 a set for 3" SS two flanges and a clamp. I really like how they slip onto the pipe and have a locating flange on the inside.

Those who use v bands, what are you using and why?

Thanks