Rings-as-cost is usually a tricky thing to get right, because you risk making your character too weak without rings, or being stuck grabbing everything to get basic moves out. I feel this mod does a good job at not being too taxing on your ring costs, and his natural magnetism makes collecting rings in groups much easier. He may be weaker without rings, but slow fall is a decent enough ability on its own, so you're not left in too bad of a state when dry.
I also like just how cranked he gets when you turn on your rung consumption, as it feels like a real gear shift. You have incredible power at that cost, and you are in full control of it. And with Overdrive on, you can just splurge on your moves, it feels pretty darn good! My only real issue is that your ring consuming flight uses the BASH flight sound, which is SO obnoxious to listen to for this long. There's a reason why the normal Metal Sonic's hover is silent. If you can't find something less loud to use, I'd rather it be silent too.
While I think the mod is good, it doesn't go much higher than that for me. It takes a lot to use a character mod that's an alt form of an existing character with recolored sprites, and this one is not really something I can find myself going back to. But I still had fun with it!