A week ago, I received my FlashForge Creator Pro 2016, and while I have been very impressed with this machine's performance, there are some things that could be improved.
For starters, it's very difficult to fit filament spools from other brands in the included spool holders, but that was easily solved by printing http://www.thingiverse.com/thing:1001925
In a related note, the default position of the guide tubes is a bit awkward and it might allow the filament to tangle. So, I decided to print http://www.thingiverse.com/thing:1055138
To my surprise... it doesn't fit on my machine. It seems that, in the 2016 version, the spacing between the clamps that hold the filament tubes was increased, and so I decided to re-make this design in SolidWorks.
After testing this design for a while, I decided to make a new one from scratch: http://www.thingiverse.com/thing:1557250
I strongly recommend the new design, as it looks better and it's easier to take off the printer bed!
While it can be printed with 10% infill, I suggest increasing it to 20% to ensure the strength of the piece.
You don't need to use supports, but they are recommended to avoid warping