Impedance don't say much about how easy to drive it is more about the efficiency and how much mass is being moved.
No idea how efficient the gx is. Just try it on everything you can get your hands on. My old lcd 2 did love power. Wasn't picky at all just wanted power lol. Loved the speaker taps on a cheap receiver I found. Not the safest approach if you have kids around that love to turn volume knobs
It sounds a bit mellow but still pleasant underpowered though but there was a big difference there.