Eureka: a better relic grind?
I think my feeling about Eureka is currently: it's (much?) better than the previous relic (or other) grinds, and kind of fun (one Anemos i355 weapon so far and will almost certainly do more.)
Atma was universally reviled when it first came out. Personally, I particularly loathed the Crystal Sand/Vilekin phase of the Anima weapons. And although it wasn't strictly a relic quest (and I leveled up several random jobs doing it) the Yo-kai FATE grind was also a kind of evil madness from hell...
Eureka, in contrast, seems a lot faster/smoother than Books/Atma/Light/Aetherial condensation/Vilekin/etc. farming and it's somehow more fun because of the danger and all of the FATEs being in one big zone, and needing to be in a party.
Eureka also got me to play more RDM, which I hadn't really done before; and it may get me the good samaritan achievement also!
Although it was possible to level up while doing atma or light farming, this is built into Eureka and it gives you benefits and makes the grind go better over time, which gives a sense of progression. (Yo-kai actually got worse over time, which made it even more frustrating.)
I like how we have at least 3 (!) paths for i350 gear - Sigmascape, Eureka, and crafted!! I wish they were a bit more diverse in terms of things like set bonuses or non-stat based secondary effects (e.g. resists sleep, reduces enmity generation, increases ice damage, boosts movement speed, etc.) but I have sets of all 3, and it's nice to have options.
But the best thing about Eureka? No heavy status when you get hit on a mount. (Heavy+Sylphlands fans will have to wait for the next area probably... ;-/ )