Howdy. I have a G12 w/ a H105. 53 max, 28 idle. Unless you're planning to go HAM on the overclocking, you should keep perspective that different makes of cards will have varying temperatures, and further, keep in mind that IIRC the throttle only begins at about 90C on 1080 cards. So you've pushed it down just fine - you've literally got like 40 degrees of leeway.
Further, for any of the water coolers, because of how that all works, you're going to see much greater benefits as temperatures climb - they always hover a bit high on idle, but if you took the comparison vs. load, you'd see a pretty solid decrease.