I think NoHo's idea isnt such a bad one. Of course, I dont think it should be "The Amazing Race: Alpha Males edition", but its not such a bad idea for a show. Yeah, its kinda like Eco-Challenge, but its more of a blend of the two ideas. You have world travel, more of a "treasure hunt" style/mentality, more physically demanding tasks/competitions....I would probably watch, or at least give it a chance.
Keep TAR how it is with a diversity of teams, the "drama" of the relationships, and the personal victories during every leg(an individual overcoming their fear of heights to bungie jump when someone has got to do it is great tv), and of course, Phil. But why not spin it off or expound on the idea and have an even more mentally and physically challenging show....where first you have to climb the cliff before you rappel down....where all of the "next clue's" are hidden, and you have to figure out a hard puzzle/map to find them....you get the idea.