SO what I've gathered from this thread is:

Synth time:xp ratio is Way Off

Synths Feel like random luck

Leveling is not engaging

Cost is to high

and my input,

There are not enough viable recipes

and

There are not enough ways to gain XP outside of the grind (DoW get Quests, AG Leves, GC Leves, Behests, Raids, and Parties)