Tour of Houston was very good - it was a rainy day so appreciated that we had alternate enclosed bus rather than the double decker however on a sunny day it would be an awesome way to see the city. Host was very informative. This is NOT a hop on-hop off tour. Takes you thru the historical district, theatre district, financial district, stadium/convention district and museum/medical district.
Then transfer buses and off to Galveston - due to lower numbers we went as part of the tour that got dropped off at NASA. Unfortunately it was a very rainy day so unable to enjoy the beaches and boardwalk in Galveston but did some dining and walking thru the many, many gift shops (Galveston is a cruise shop port!). If it was a sunny day, the amount of time on the island is not enough to spend a day bath beach, so to speak, I would suggest of going to Galveston for that purpose, rent a car or get a shared ride (Lyft/Uber) and go for the day.
Tour bus driver was good, very friendly, funny. Family run business. Easy to find the pick up point - close to all hotels in the area of the convention centre/stadiums. Definitely recommend.