Thank You Starbucks

Recently I had a poor experience at Starbucks (I don't go there too often, but I had a gift card...)

Anyway, I filled out a comment card and explained my problem (I would (maybe) have spoken to the manager when the problem occurred, but I was in a rush.

They wrote back with an apology and a card for a free drink.

Now, should I use that at the same location where I had the problem, or should I use it at a different location?  Part of me wants to avoid the one location, and part of me wants to see if they actually got it fixed, or just decided to placate me.

Thoughts?

-- Andy