I bought the GP version for a day, and I really enjoy it. It's the best GP bullpup rifle out there. The scope is pretty crappy, though. I've never been much for the AUG A1's scope, but it's accurate enough to do its job well. The recoil is pretty manageable and it feels similar to the G36E when using it. It's a four-hit kill but for me that isn't a problem since I always shoot for the head at a distance anyway which is where I get all my kills. I swap to a CQC weapon like my MP7 MOD or M4 Super 90 when I get that close.
Overall it's a pretty badass looking gun, although it's a bit loud. I bet the NX-S version fixes that, since it looks like it has a suppressor. I have no idea about how bad the recoil is (because like I said, I aim for the head at long range or I tap fire so recoil affects me very little). Spread pattern isn't nearly as wide as the G36 to compensate for an extra shot to kill, so it feels very balanced.
It's not the best gun out there but it's a fun one to use. I'm probably going to add it to my permanent arsenal at some point.