I have a Glock 20 Gen 2.5
It has features of both the Gen 2 and Gen 3, mainly having to do with the grip.
At one point someone tried to list all the Generations and the changes in the features that made a given Glock a Gen (?) model.
Mine was listed, but there are damn few of them, like mine, out there. I can say that other than an ammo issue (fail to fire) I have had 0 issues with it. I carried it as my duty weapon for 5 years.
