I honestly hated Eureka. People spent most of their time AFK waiting for a certain boss to spawn or were busy training NMs or light farming. Baldesion Arsenal was fun, but incredibly expensive, unless you played a DPS - another feature I didn't take too well to. I also hated the separated leveling system and how it promoted solo play over your friends if you were more than 2 level apart.
The relics were released entirely too late, even following the trend of relics-can't-be-the-same-tier-as-savage-weapons-for-whatever-reason. I hate relic being tied to this instance, too. I'm done with savage for the week. I want to grab some of the past relics from Eureka, but I mainly can't because it's dead content. It was never tuned to progress at a reasonable rate solo, especially after the nerfs and buffs they put in that made trains that much more efficient. I've heard they plan on making nerfs to Eureka in general, but in the meantime, this is all freetime I could have used to grind out those relics.
Equipment drop rates were abysmally awful, despite being BiS for the instance. Considering you have BA in the place, I find that to be problematic. The difference between someone with no Eurekan gear, someone partially geared and someone fully BiS was leaps and bounds noticeable.
While I think some posters in this thread are looking at the content with rose-tinted glasses because similar to XI or what-have-you, the instance had issues. Boy, did it have issues, and it's not like they were experimenting on how to get it right. They got it mostly right the first time with the first iteration of Diadem. For some reason, the XIV team doesn't want us working together and made one of the worst decisions that butchered Diadem 1.0 into 1.5 and then 2.0. Eureka is just Diadem 3.0 with most of the mistakes from 1.5 and 2.0, despite having the player feedback from then already and getting the same feedback the second time around (Diadem 1.0 was very similar to Anemos, 2.0 a lot like Hydatos and 1.5 was Pagos, but worse). I can't say I have much faith in Diadem 4.0 nor do I look forward to more Diadem or Eureka.
Baldesion Arsenal, however, is another story. I do look forward to more of that.
How did Gordias and difficulty even get brought up in a topic of Eureka of all things? One of the most brain dead pieces of content there was.