I've heard nothing but good things about them ... except that their minimum transaction level is high enough many/most/all??? startups can't meet it. So the latter obviously go to Paypal and when/if larger Auth.net.
Braintree is asking those companies to make it easier to "graduate" to Braintree. Since Braintree provides one of the highest quality services in this field, they're obviously not worried about too many customers defecting, or at least not until they get so big they bring it in house.
Which in the current startup capital climate is going to be very rare, I suspect.
