We tried a Runnerbean Tour our first sort of jet lagged day in the afternoon. You meet in Placa Reall (spelling may be wrong) in the Gothic. They appreciate reservations in advance. We did the Gaudi Tour which included some metro travel. The guides are just about as friendly and knowledgeable as I have encountered on any walking tour. We had a very small group maybe 8 and the pace was really nice. I would highly recommend a Runnerbean tour for an great introduction to either Gaudi or Gothic BCN. You tip at the end and thus they have a huge incentive to make the tour as fun and informative as possible and really love the city.
It was easy to give a generous tip as it was a bargain to say the least.
The only con and frankly not really a con when you are just looking for an overview of the area is they do not go inside the buildings. To be honest some tours charge a fortune and do not go inside either. As long as you know that it is good.
We intended to go back and it is a good way to plan your further sightseeing on your own.
I highly recommend this company and while I fully realize they are not licensed etc. they are running a great operation and very very professional.
We also did other kinds of tours with private guides and one group so I know the differences and while all are good if you are on a limited budget (many of the participants were staying at hostels) or just looking for a great intro as we were Runnerbean is a good choice.