Mechanically, I think they are largely fine. Sure they could be more challenging or interesting but I don't personally mind the majority of them being fairly mindless.

Better rewards would be nice, even if just in the form of expanding the bonus XP stuff to all zones. Some sort of reward for doing enough of them would also be nice, akin to the Shared FATE system in ShB.

I would also like them to be quicker to complete solo, since that's how you often end up doing them. The participant number scaling just seems off. A group can blitz through a FATE in a couple of minutes but if you do them solo it can feel like it takes forever, which just further discourages me from doing them.

Oh, and it would be so nice if, as in all sync down content, you didn't loose your tool kit when you synced down for them. I don't mind being powered down to match the FATE but it just plain sucks to lose half of my abilities.