I wouldn't expect amazing scale there. Look to arena, 12 wins award is not exactly too much better than a 10 win. And it takes quite a bit to get there.
Yeah, and the ranked reward isn't even actually that good compared to arena. I was considering playing more ranked this month because of this but looking at the reward closely it's not really worth the time compared to say just playing arena with infinite gold. I guess the best way to determine how good the rewards is to see if Kripp is going to bother even reaching rank 5 this season Kappa.