Alterra: Kings and Queens of the 'Spresso Machine

I've been drinking a lot of espresso lately.  The espresso served at Alterra is in a league of its own.  While other coffee shops pull shots that may be very good, they usually taste more or less like very strong drip coffee.  They do not give the flavor explosion sensation that Alterra's espresso consistently provides.  However, there is a certain degree of variance even between Alterra locations.