^^ As far as super clamp manufacturers, the Impact version is built every bit as well as the Manfrotto, IMHO, and the parts are even interchangeable. I've owned both and it used to be that the only practical difference between the two is the longer handle on the Manfrotto gives you a bit more leverage to tighten it, whereas the T-handle on the Impact version is a little easier to manipulate in a tight space. Impact now also offers a long-handled version similar to the Manfrotto, making the two brands nearly identical. Both excellent and virtually indispensable to our hobby, just a matter of preference.
And yes, the Impact version of the 012B pole/base works just as well as the Manfrotto at half the price. The Manfrotto version may have a little more heft to it but maybe not enough to warrant the price difference.