Is there any benefit to the crafted rune-stones that take a cracked Rhi Helvarch sigil over using a dropped rune stone? I'm trying to decide if I should craft my own or not...
The stats will still be completely random like drops right?
Yep, stats and legacies are still completely random on identify. The only real point of crafting legendary items is to get your level 75 second age, once you get a worn symbol. I guess you could use a sigil to make a 75 third age if you really need one and can't get a drop anywhere, but there's not really any need for it.