We have eaten at Tempranillo's 3 times, once last year on our first visit to Basalt and twice this year. We would not have returned if the food was not good. There are too many good restaurants in the Aspen valley to want to repeat a poor dining experience.
I'm a pasta lover and they do a great job, al dente with delicious sauces. My wife has had dinner salads which were also very good.
Our last visit we went for happy hour for tapas and glasses of sangria. Again, delightful.
Also, we have sat out on the covered front porch each visit. Very charming and special. There is also space to sit in the shaded front lawn for drinks and/or appetizers.
Re service, I don't know, we have always eaten there on off hours when not busy, so it is easy for staff to give good service. I don't know how that might change during a rush.
If you like good food in a truly charming setting you will not be disappointed.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.