This is the first I've heard of these high yield checking accounts. I searched credit union high interest checking and found one that pays around 2% without strings attached other than direct deposit, 3% if you spend $500/month on their credit card, and 4% if you spend $1,000/month on their credit card. Sounds like an awesome deal if you just set up a $1,000+ payment on their card, like mortgage or something. Easy way to make 4% on 10k worth of emergency fund. I'm tempted to do this for the $400/year free money vs the $50 I'm making in my "high yield" savings.
Then again, its another layer of complexity for $350/year. Would be a lot of work to switch all accounts over.
That's still a crazy good rate compared to the current norm.