I have to disagree with this one and it's basically why i don't play it full time.
With elite specializations and balance changes, your best gear stats change. Their balance wasn't good, for example, just recently mirage was bugged and out of control and they ended up redesigning core mesmer mechanics. The raid buffs situation has also led to stacking of certain classes making it almost impossible for others. They have been working on it and it's getting better. But balance is not really as "tight" as in WoW and when they change your class/spec and you now need a whole new set of Ascended gear.. it's soul crushing.
It can at least be traded between characters, but a balance patch can easily knock you off raid viability and into grinding for a new gear set for weeks. It's not a very good feeling and legendaries are horribly expensive and time consuming to make.
There may be a way to change stats of ascended gear on the forge? I have no idea because another problem of the game is that it hardly explains how anything works and extensive out of game research is needed. And, i don't mean raid encounters, but just game design.