I have the Rival, and actually, while it's a good benchmark ball, at OOB it's not very early at all. A decent midlane with a decent pop. I think the GI is actually very similar to it and there's not much one can do that the other can't. By nature the GI might be a bit stronger since it comes polished and can still outhook the Rival in my opinion. I have my Rival at 2000 though because I wanted it a bit smoother, and I feel at 1000 it would give the reaction you're assuming, in which case having them both could be a pretty good combo if you're just looking for a different reaction. If you were looking for a step down from the GI but is still smooth I'd like into a Street Rod or Pluto because I think Rival is not much of a step down from the GI.
Hope this has helped, weren't sure if you were looking for another ball to go with that GI but thought I'd share my thoughts on that.