Well, to my mind the biggest difference should be how you treat the people working on the project. I have heard different gospels about how people were treated

Well, to my mind the biggest difference should be how you treat the people working on the project. I have heard different gospels about how people were treated and felt either compelled to their horrible slavery tasks or honored to be part of the construction of a holy monument of your revered living-human-deity. Now the biggest challenge today would be probably to sell the project politically: even Mao and Stalin didn't have the political power (or will) to waste so much resources on such a useless rock pile – tourism and archeological documentary apart.