My mother has mobility problems - she can walk a short ways slowly with a cane and we had borrowed a wheel chair. Mati met us at the ship with an incredibly clean van that included a step to help Mom get into the vehicle. We had a 4 hour tour of Tallinn that included areas outside of the Old Town. Additionally we got to learn of the rich history of Tallinn from a native Estonian. He took the time for us to view the sites and to understand all the history that has impacted Tallin. I would take a tour with Mati again as we felt we got excellent value for the cost (195 euros for the both of us for 4 hours).
Thank you Rick for recommending Mati Rumessen in your guidebook, which is an outstanding book!