Everything is the same the only difference apart from stickers is the end plates on all of them
Mag slidey, mag extra has more magnets,super mag was slidey with ceramic bearings inc in box.S mag extra ceramics and knob to adjust mag rack instead of slide plus a bigger mag aray but breaks often as slides on plastic pins so flexes then breaks where brass adjuster is threaded.
My one broke whipped it all out snipped pins off then put a mono mag kit in it.