so many variables.
1. Where does the coffee house get their coffee and how often do they restock and use fresh coffee beans?
2. Do they ground in house or made to order or is it pre-ground?
3. What type of milk do they use? and yes, milk does make a difference when making a good quality espresso.
4. How well does the Barista know the machine. There are ways to burn coffee, and to burn flavoring. How does each barista prepare their coffee.
Any of these could effect the quality of espresso at any number of coffee houses.