Simply put, I want to retire my 2 pairs of dated road shoes and get a pair that I can ride my mountain, road, and tour with. Weight would not be as much a concern as comfort, durability and a shoe I can walk in.
Specialized Tahos are nice. They look kind of like real shoes, they're comfortable, and have real soles. I've toured, commuted, mountain biked, hiked in the desert, and done lots of general riding in mine.