I loved watching their first trip ('Round the World) and fizzled out a bit into their second (Africa) trip. A great series, though and totally worth watching!
You can watch all the episodes on youtube, starting here
and following through each section.
I found myself thinking that they allowed themselves to take on too much "extra stuff" (in my eyes) like the people, gear, and support vehicles. Often times I felt like their trip would be easier if they didn't have so much stuff with them.