I had one of these and it worked really well.
Its designed to go on MOLLE gear, but you can put it on your belt just as easily. I had single stack 1911 mags in it, and the magnet was strong enough to even hold them in without the strap if you turned it upside down. They do make them in black as well.
They also come in single and triple mag configurations.
After using it, I don't see any problems arising from the grip extension on the XD. I'm actually thinking of getting another one myself for when I carry my XD40 or my 92FS.