With OSMs you can truly recreate any mode found on any other chip out there, or create your own. The NEO code is pretty intuitive and programming using arduino is simple enough.
I'm not a huge fan of the rubber casings that came with the chips, they are a little uncomfortable until you get used to them. Sites like KandeKreations will also have their own casings coming out soon and those should be a little better.
There are some bugs found here and there but they are all software bugs and the creator (Ramiro) works diligently to solve issues and provide updated code!