Quote: "Man, I can't believe the size tool box these older versions have. Does anyone still use this older software? And how does it compare to the new software? "
Yes quite a number of people still use FPS Creator. It has quite a number of features that are still not a part of Game Guru yet. Though FPS Creator is indeed, its predecessor. FPSC is now a free open source software. It has many limitations however and is mostly designed for interior world building. It did however come with a full particle system.
Here is a recent image from Mrigaya using FPSC:
In regards to Game Guru, I was expecting particle support to come much earlier than a lot of other features that came about such as the character creator and multiplayer. Its an essential tool for any 3D game creation. Currently we are stuck with using snow boxes and rain boxes to mimic such weather particles. Mind you these weather boxes are very well done.
The same effect as in Unity could be created in FPSC as in later versions an overlooked particle system was added. Here is a bad example of me testing it out:
FPSC fog particle tests by nbtmon:
FPSC snowflake particle test by tonando: