Like most things in life, I think it's a matter of taste if you think Eureka is fun or not. I'd say I wouldn't be surprised if there was a survey done and the vast majority of people didn't like Eureka.
But, for people who do like it... well, good for them. There is content for them.

I'm more at issue with the way some aspects were implemented. Essentially not allowing friends and groups to easily band together because of the huge exp penalties or overall combat in-effectiveness seems a very opposite approach to the way SE generally tries to design everything else in the game.

The FATE train can be debated over and over, but it's just kind of a fact of life now. They could change it, but I think it should be left in there because if they fixed the real root of the problem (people can't really effectively get groups in any other form reliably), then the FATE train wouldn't be the de-facto best option.