I'm perfectly happy with my Ally 2.2% savings account+ numerous cash back credit cards but this would be a neat card for someone switching over from Wells Fargo/BoA with their atrocious .1% savings accts.
2.0% on all debits is a much larger number.
I have about $5,000 coming into my checking account every month, which I then use to pay rent and several credit cards with % cash back bonuses. Whatever is remaining for that month, I transfer to Ally's 2.2% account.
Unless I'm misunderstanding your point, I don't think I would be better off switching to this card because my checking balance is volatile and is usually close to zero.