Tommy is a delight. We had a great time walking around and trying local food in very local places. He's knowledgeable and proud to be Vietnamese. You can ask him anything and he will likely have an answer for you. Make sure you also visit his coffee shop in the train street, called Kmin.
Not the best walking tour I've had. I liked Andreas' enthusiasm but this is a "walking tour". We barely walked 1km and stopped every 20 meters. It was more of a "standing tour". The places we visited were not of touristic interest.
Iñigo was a great guide. He was fun and informative. I would recommend this for when visiting Bilbao.
If you are looking for an English tour, I do not recommend this one. The tour guide was friendly and was trying hard, but her English was terrible and hard to understand. I honestly think I understood 20-30% of everything she said and, at the end, I wasn't even trying anymore. Also, there was no connection between the participants and the tour guide. She didn't ask anyone's name, place of origin or tried to connect in any way. I've taken a few dozen tours in various cities and, unfortunately, this was one of the worst ones.
We signed up for the 11:00 English tour and, after waiting 5-10 minutes in the huge line, when they came to take our names, they said that the tour is only in Spanish. When I showed the guide that we booked an English tour his reaction was basically "not my problem, go to the tourist information office, good bye". I do not recommend it.