I made my editor for 3dgs, because I need special AI related things to see visually at design time, so I can make my levels lightning fast now. this was also good for making my own standards for menu panels etc. of course this part could be much better... I also can work in unity fast, e.g. made mesh based tree shadows taking into account sun position within a few days (I mean a few work hours), but I simply won't pay so much money for unity pro to get the missing features...