DjangoReinhardt said:
Depth isn't determined by the number of mechanics in a game.
Yes, and that's why I put more than 1 sentence in my message!
Adding more layers, by definition, does increase "depth". If this Gem system adds another layer, like the trailer says in such a marketing-happy way (about judging your opponents fighting style based off the style of gems they have), then we have something more unique to this game, than straight-transplanted SFIV and T6 elements. You just might be able to tell more "at a glance" when playing with randoms online, than you do in your other fighters ATM.
The number of systems, personally, doesn't bother me. It'll all be second nature after you get used to it. We know this from years of playing fighters, right? And with it seeming that each character only has 1 Stand alone Super move, all this other stuff is just taking the place of "multiple supers" or "selectable Ultras", in a bit more efficient to produce way.
As much as players don't like what the designers put into the game ("X-Factor is DUMB!"), I like the idea of being able to give my character the X-factor (in traditional sense, not Marvel) that I want them to have.
"I don't care if her zoning is great! I just want her to have more HP, and a better poke!"
"It doesn't matter if he hits hard, if he never gets in to hit!"
This, potentially, can be a system where you get to decide these things, on a whim, per character, per fight, per team. The idea, in general, sounds pretty nice, to be honest. But it'll be interesting to see how well it turns out.