I've seen all those before, yep.
#1: I don't mind the inaccuracy of the feathers not being near the hand, personally (though I can see why it would bug some). But the poly count and texturing is atrocious on that one, to me.
#2: That one seems like a really cartoony model in general, but also falls prey to: http://dinogoss.blogspot.com/2013/06/youre-doing-it-wrong-cgi-feathered.html
#3: Okay... actually this one is new to me! Overall I like it, from the vertex count to the general way feathers are handled. We'd have to re-rig it to match our existing rig, but that wouldn't be the end of the world. I'm not an enormous fan of the way this is textured, though, so in order for us to use it we'd have to pretty much retexture the body and the feathers (the snout has some awesome details, as do the eyes, though). That might be something we do if we get a chance later on, but I'm not sure how well we can do that without the original source files; mesh painting of the zbrush style doesn't work without a highly subdivided mesh. Mudbox might do better, I'm not sure.
#4: That's getting pretty far from being a raptor, and I've seen this one before. I like it, and the idea of having that sort of thing and an archaeopteryx as playable things is appealing in the same way a t-rex is. Biggest problem with this specific model is the texturing is super cartoony again.