I had no idea this even existed, but apparently FobusUSA makes a version of their Evolution Holster for the GP100. I haven’t used a Fobus holster for quite some time, however I have heard anecdotally that on the newer Evolution series holsters they have corrected the issue with the plastic shearing off around the metal rivets. I don’t have any knowledge of that, but it would be interesting if they had.
The advantage of Fobus holsters is that they make holsters for models of firearms that are not necessarily commonly available; that being said I don’t currently own any Fobus holsters. Fobus has never given me anything, and all the Fobus holsters I’ve ever used I bought and paid for with my own money. I’m kind of curious about the GP100 holster though, because the GP100 is such a heavy gun it might be neat to see how well it carries in the Fobus, if it can distribute the weight well.