Easy of setup, fast rendering times (at least when using GPU), very intuitive interface with great documentation; even though it's only available as an online service so far I really like this software! Nothing in particular except maybe that at first you have no idea how all those tools work together but after some time everything becomes clear again ;). Great tool if one wants realistic looking people without having them spend hours doing photorealistic renders or paying expensive artists/models etc.; just create models from photos taken by yourself easily enough - which is not always possible since most real-world environments are too complex anyway ;).