Any leg/set items <61 will able to be broken down to brimstone.
I would imagine that most will be useless once you have RoS with a few exceptions mainly for twinking, especially the Inferno level Whimseyshire items with damage rolls (as I believe new Whimseyshire legs will roll at char level rather than lvl30?) and pre-loot2.0 Hellfire rings.
Haven't got any Hellfire rings yet, but got a nice 600dps Spectrum
Any leg/set items <61 will able to be broken down to brimstone.
I would imagine that most will be useless once you have RoS with a few exceptions mainly for twinking, especially the Inferno level Whimseyshire items with damage rolls (as I believe new Whimseyshire legs will roll at char level rather than lvl30?) and pre-loot2.0 Hellfire rings.