Really looking forward to your Xero integration, that's currently a must for us (daily sync so we can reconcile customer invoice payments) otherwise Mercury looks great. The Big Bank we use right now don't provide sending ACH or wires online, you have to call them and they give you a confirmation call back about an hour later. It is a giant pain in the behind and completely ridiculous in this day and age.

Once you get automatic Xero sync working we'll be there!

Mobile app = table stakes these days. I think though that Mercury being a place to park cash for startups and earn interest to off-set SaaS costs could be worth it though. You might want to think about a tier where if startups maintain a minimum balance of $X, certain partner services are included for free as an alternative to earning interest.