Honestly some of the biggest draw-backs for GG would be the lack of
a menu creator helper-- though someone has made this for the community
(is it free?) Sounds are another manual insertion technique that would be
so easy to add by properties of the object-- though I could see the flexibility
being required filled by scripting covering it better. Not afraid to script- but
there's those suggestions. Menu screens is a biggy. The widget can get
wonky... and there needs to be a "Hide Floors" button in the GUI so that when
you are inside a large building and want to slide a several group of objects
to another spot (without trying to separately select them all) -- you can hide
the floor and lasso them all (some people call it rubber-band the group?!)