We booked BAW's Gaudi walk before we left for Spain. It was easy to do and Miguel from BAW was prompt replying to questions by email. The only public Gaudi tour BAW had scheduled during our stay was on our last full day in Barcelona. Since the BAW tour included just the exteriors of the Gaudi buildings, the days prior to the tour we visited the interiors of the Gaudi buildings on our own.
By the day of the BAW tour, we were 'Gaudi'ed' out and we considered canceling or seeing if we could change to a different tour but we are so glad that we did not.
Joan from BAW was an excellent guide. We were extremely fortunate that we were the only ones on the tour that day. Not only did we learn about Gaudi but we also learned about the development of Barcelona and its Eixample neighbourhood. Joan covered the development of the modernist movement and pointed out interesting architectural elements and city planning concepts. He patiently answered our questions and explained concepts very clearly to us (though we love architecture neither of us has a background in the field). The time went by fast! If we visit Barcelona again, we will likely try BAW's other tours as it would be interesting to learn more about the city, it's architecture and development ( past, current and future). It was great to walk the beautiful city with someone so knowledgable about its history and architecture.