UPDATE: either the food has changed, or my perception has.
This time the (Classic) burger was really good, with a nice balance of meat and toppings. I didn't notice any lettuce on this one. The bun had a good, meal-y quality to it - nicer than the everyday white hamburger buns most places use. The fries were nicely browned, and generously salted. No Coke Zero :-(
The staff deserve a mention for offering excellent service - very friendly and attentive.