With the other one being much better with shift gear, what would it even be used for? It has venom drench, which is an ok move, but a 4× weakness isn't good for something with so bad bulk. I mean, what good is it really?
Low Key is harder hitting special, but more limited, I think.
Low-Key has the move that lowers attack, special attack, and speed which can be used for support.
With that said, however:
Venom Drench is very niche and Magnetic Flux is pretty useless because of it's speed, low defenses, and it mainly works for team battles.
So Low Key is a bit better for support, but Amped is better overall.
Source
Hope I helped!