Not sure if Fedora 26 has been officially released yet but I installed it on my test system yesterday. Barring a couple of mistakes I made the upgrade from 25 -> 26 went smoothly and so far nothing broke, everything seems to be working just fine. In a couple weeks I'll upgrade this system to F26. This system I use for productivity so I like to upgrade a similar "test system" first before I commit this system to an upgrade.