Yeah I know what you meant. The only difficulty that I had mounting my H100 was getting it on straight. The cooler's tubes are rigid (which is a good thing) but this also means that there's not a lot of flexibility. The standoffs which hold the cooler to the motherboard are also a little bit on the short side but as long as you get a nut on each one and then tighten them down it will sit just fine.
I do not know if there is a difference in mounting the H80 and the H100 but I had no issues with the H100
EDIT: Unlike other motherboards the RIVE (and perhaps other LGA2011 motherboards) already has the necessary backpanel attached to the motherboard, just thread the provided standoffs into the holes on the motherboard and drop the cooler on top