I tip because they (Gold,Mobility) deliver directly to me, take their time to explain how the scooter works, takes the time to adjust the scooter to my comfort level. But most importantly when I rented from them, the time I scheduled and we (them and I agreed to), I and Magical Express were running 15 minutes late. They were still waiting for me! When I get ser vice that I feel is definitely above and beyond, I most definitely tip. (Yes, I tip for regular (any) service whether it be mousekeeping, a server at a restaurant, or bell services).
Having said that, tipping is at your discretion. You will meet many wonderful people willing to make your vacation "magical".