I made a couple of Barcelona tour, and this us the one I really recommend.
I enjoyed the tour a lot. Even better that would be if there were other tourists joining 😄. You'll discover a lot of nice corners worth visiting.
We are Germans, so our rating is quite hard 😄. The experience was very smooth. We had a small group and there was no problem walking around. Sebastian is very knowledgeable, he builds his stories in an engaging manner, so you won't be bored.
You have found it, no need to search further. One of the best guides we had in India. Bala took care of our tickets, riksaw, but the main - shared a lot of information and fully answered our questions whatever we were interested in. He went extra mile to show and explain us everything during those four hours. We didn't notice how the time flew, to be honest. It was very interesting and memorable. I wish we had more time for the alternative route as well. Many thanks and best of luck!