I got offered a Stripe Advance and did a little spreadsheeting to determine whether it was a better deal than the line of credit I'm currently using.
Crunching the numbers based on my current net and their repayment terms, it looks like all 3 offers are designed to repay in roughly 12 months assuming flat revenue. 10% fee over 12 months is--you guessed it--a 10% APR. My current debt (I purchased my business on a line of credit) is at 5.5%, so for me personally the Stripe Advances don't make sense.
I could see it being really useful for companies that don't have access to cheaper debt or companies that need it to fund inventory/ad spend, though!