We were unsure if this was going to be worth the time and money. After all, we had already had a few days in Madrid and had taken a couple fabulous walking tours (rooftops of Madrid and the Markets). Nonetheless we wanted time off our tired feet. We wouldn’t feel like we were just hanging out in our hotel if at least we were driven around.
Boy are we lucky we booked this. And, both my husband and I urge you to go for the full 4 hours. The private gave us plenty of chances to relax and ask advice, get questions answered, not feel either pushed or held up by others. The tuk tuk had extremely comfortable seats, worked quietly on electric, and the open sides were conducive to having a nice breeze (but a blanket was provided for the chilly time in the morning. Easy to catch nice photos. We were able to walk around as we wished—the Egyptian tomb, the cathedral.
Our guide cared about our desired pace and interests, took us to an amazingly large range of the city that we never would have walked, and was able to make informative historical commentary along the way.
Don’t hesitate—book it for 4 hours.