This is my main setup and I find it massively easier to use than a stand most of the time. It also makes venues happier.
I've run DPA 4021 from it and AKG ck9x caps in an active rig, as well as even a 4-mic setup with the DPA on top and some Neumann 150s clamped to the extension pole.
I find that sometimes if I clamp to something with the stud pointing up it can be a touch less stable. I find that steadying the clamp with the bar already in place while I tighten helps.
However, for a more sturdy setup, I find it's better to clamp with the hole horizontal and run this out of it:
http://www.bhphotovideo.com/c/product/546373-REG/Manfrotto_by_Bogen_Imaging_042_042_Extension_Arm_with.htmlThen, with that facing up, attach the manfrotto pole.
This is what I prefer to do when I can. I find it offers more stability. When I did the 4-mic, I was running this way. It will still wobble a touch more than a stand, but not enough to affect your recordings. I would recommend getting a decent pair of shockmounts, just in case.
Good luck.