The holder can be expanded and contracted according to the size of the bumper/case. It can go as far wide as a Galaxy Note + Elago thin case, no problem.
I had to remove the iPhone 30 pin charger (there's two screws and a bit of glue, it's hard but doable), I did that and I could put it back again if I needed to. Now I have to figure out a way to stick out the Samsung charger through that hole, but that's is waiting for a case. I think just a piece of wood (painted black) with foam should be enough to hold the tip in place. The phone itself would be held by the sides of the case.
Better than sell the iPhone dock (very new) and now I have a flexible case to boot, it could go well with any usb phone with charger in the bottom, I think.