The gear system is something to worry about and potentially could be a great thing or an incredibly bad thing.
But I'm positive and I hope it will be something like variation system that enhance only one aspect of the character beside other and maybe it can be used only for a limited time (like a trait or something like Killer Instinct instinct mode).
So, for Superman, for example, a gear can boost is damage, give him better zoning with is laser, add damage during freeze or give him better air mobility.
This can be hard to balance but without OP properties and with some limitation, it potentially be a really good thing that add strategy and variety to every match.
And I'm pretty sure that will end with everyone choosing the most powerful gear for their main with no real experimentation! :'(