My favorite thing about cruising and the main reason I do it is walking laps on an outside deck and looking at the ocean. So, I've been a big fan of the Grand/Crown class ships, with the full wrap-around Promenade deck. Until a few weeks ago, I'd only sailed on the Royal and the Majestic, and I found the walking/jogging track on deck 18 to be a fairly good substitute although there were some flaws. A few weeks ago, we sailed on the Discovery, and I'm a complete convert. They've changed the track on deck 18 somewhat, removing choke points. It's mostly wide enough to get around the folks who insist on ambling around very slowly and four abreast. Don't mind the ambling slowly, but it's really frustrating to get behind them and not be able to get around them at all because they simply won't move into single file or even double. I don't move at lightning speed either these days, but I'll always move over for people to pass. On the Discovery, I think that deck 18 track is a thing of joy.