I watched it, and was left with kind of a "meh" feeling. It was disappointing, because I really wanted to like it. I just think that introducing the whole electric vehicle concept into the production was such a distraction, and drew a lot of attention away from the actual trip. Every episode seemed to at least partially focus on "how far can we get with this charge? Are we going to make it on this charge?". Moreso than the previous two documentaries, they seemed absolutely tethered to civilization in this one because of the limitations on their vehicles. There was definitely no "Road of Bones" equivalent for this chapter. I think that this documentary did show the potential of electric bikes, but what it really showed was that currently, that potential is pretty limited, at least as far as long distance travel is concerned. I certainly understand the motivation behind the EV themed production; they had to come up with some kind of "hook" to get people to watch, especially in light of the fact that they'd already done two of these documentaries previously, and the last one was 13 years ago. The EV's were a detriment to the production, however; their problems and limitations became the focus of the series, rather than just providing another sense of adventure the way some of the breakdowns in the original two series did. The documentary wasn't about the trip, it was about the vehicles and the technology.
I also felt like the interplay between McGregor and Boorman felt a little more forced than it did in the first two. Not surprising, since by their own interviews they'd kind of fallen off each others' radar in the intervening years since Long Way Down, until Boorman was injured in a motorcycle accident. Their friendship seemed less genuine in this one, and more of a relationship of convenience and financial benefit.
I've watched Long Way Round and Long Way Down multiple times; I doubt that I'll ever watch this one again. I'd rather watch Mondo Enduro again for the umpteenth time.