The only set I have yet to complete are the Eureakan weapons, the main part that is holding me back is the Pagos light stage. The fact you get so many crystals, but cannot support that rate with light is frustrating. FATEs need an increase in the light that they give and, as Kisshu mentioned, change how they determine the FATE boss health.

I probably wouldn't have an issue going in solo, if I knew I could kill the FATEs and not have the be artificially boosted just because there happens to be a massive BOT farm going on.