Would be interested in the brand/model of the 1080TIs that you are getting to do testing with. I would like to get some 1080tis or some of the new Nvidia cards when/if they come out and I can get my hands on some.
I think we will be using an open air frame setup, but I know I would take the 35 db fans at 63C over the 60 db fans at 56C every day.
On GTX 1060 the quieter fans are fine for cooling but I think on 1080's or Vega 56's the only option is to go with high power ones that are loud. I am still waiting for my shipment of 1080TI's to arrive to do some testing with them.