You might change your mind if you saw the clamping mechanism. It's a large setscrew with a radiused tip pressing into a matching recess. The aluminum version provides the proper electrical relationship to the standing seam material, be it galvanized or galvalume. Grease is helpful, too.I have a standing seam roof. No way in hell I’d clamp all that crap to it. The roof metal is very thin and only lasts because of the coating. I’m not buying the idea that clamping to the seams doesn’t damage the coating.
I've installed a few of these clamps, inspected a 10 year old installation that hadn't been properly torqued. There was damage to the top of the seam where the clamp had shifted (high wind loading) but I didn't see any rust or damage to the coating from the clamping. It was old-style hot dip galvanized, dunno what your coating is.
Around here (central VT) it's the preferred installation. The PUC (the state regulator here) prefers roof mount systems, 12/12 standing seam is the traditional roof and pitch, which just happens to be the recommended solar angle here. No roofing penetrations is a huge plus. I agree, it's not ideal, but damn close.
Unirac S-5 is the setscrew version (and the oldest) but SnapnRack is a newer version that clamps to the seam without distorting it. You might like that better.