I didn't enjoy Eureka when it first came out. The main reason I didn't enjoy it is two fold.
1. I had other goals at the time besides the relic weapon.
2. My Schedule is chaotic at best and I am rarely ever on at the same time or even same day on a given week.
Once Eureka was "nerfed" I enjoyed it more as it took less time to get the items needed. I am currently in Pyros, and on the last stage of the relic weapon in Pyros (getting the stats how I want). Pyros has had a small nerf, but not a huge one yet (afaik). I am looking forward to getting to Hydatos and trying out BA when I get to it.
I will most likely do the new iteration of Eureka in 5.0 so long as they fix some of the issues 4.x Eureka had, and respond in a good way to the player feedback.