I've had my ticket for over thirty years and "Magic Antennas" have been around much longer than that. I'm all for innovation but those pesky laws of physics keep getting in the way. There is only so much you can squeeze out of an aluminum hula hoop and a box of coils.
Long ago when I lived in a small one bedroom apartment I made a loop antenna from plans in an ARRL book. It worked OK. Not great, but OK. And I sure as hell didn't pay hundreds of dollars for it. Nobody uses, as Tempstar very accurately observes, compromise antennas when they have other options.
These products are always a last resort, never a first choice. When an antenna's biggest selling point is its size and not its performance as an antenna, then it's a tipoff you are looking at a gimmick, especially at the prices theses things go for.
Anyway, I'm not looking to be argumentative, I just want to point out that loop antennas have been around for decades and there is nothing amazing or "innovative" about them. YMMV. Everyone's gotta do what they think will work best for them.