When SI1 did the trans-american flight, they had a stop-over at the Smithsonian's Udvar-Hazey annex out near Dulles and I went to go see it. I got to meet Bertrand Picard, which was really cool, got to touch the plane, and it was also a good excuse to go and see the rest of the collection.
With this aircraft, we're talking about something that has the weight of a car but the wingspan of a commercial long-haul airliner. It is largely constructed out of carbon fiber, and with proportions like this I would assume that sufficiently strong winds could cause it to snap. There are also the stop-overs for educational and marketing purposes (such as spending 3 days at Dulles with the first plane 2 years ago), as well as rest and recuperation time for the pilots. They have a large ground crew, engineering team and marketing team that moves with them. It's kind of like picking up the circus and moving it to a new city and trying to get there in time before your elephants, which are on a different train.
That said, it's one of the coolest things I've ever gotten to see in person, and Bertrand Picard is an amazing guy, from an amazing family. His grandfather was a high-altitude balloonist and scientist who inspired Professor Calculus in Tin-Tin. His father went with Challenger Deep to the bottom of the Marianas Trench. His uncle was also an explorer, Jean Picard, after whom Jean-Luc Picard of Star Trek was named. The idea for this plane came about after nearly running out of fuel during an around-the-world balloon flight in the 1990s.
Whether we'll be seeing solar air transport on a commercial level in my lifetime or not, they're definitely attacking various engineering, scientific and social problems in a high-profile way.