The main reason people love Eureka Seven is for the love story. Eureka/Renton are basically the perfect pairing insofar as mutual growth, overcoming adversity, sacrifice, overlooking flaws/physical defects (what makes the final scene so strong), conclusive ending with an actual formed relationship. This is also the case for Anemone (imo the best character in the show) and Dominic, Holland and Talho, though they receive far less attention.
If you don't care about any of that stuff then you probably think it's slightly above average if that. The character growth of Renton from an annoying brat to worth something is good, but so much of it is tied to his love for Eureka that you have to be invested in that relationship to really tolerate him. The story is fairly convoluted and again, you only tolerate it for the relationships.
Eureka Seven does have a dope presentation. The mechs ride surfboards with trailing lasers that track their every movement. The action sequences wind up looking incredible because of the fluid aerial acrobatics. The OST switches between a wide variety of styles and genres depending on the scene or arc itself. Very similar to Bleach in this way. Japanese rap with jazz blaring in the background for the 2nd OP -
I think Gundam Thunderbolt, Macross Plus are the only mecha anime I would compare it to in terms of raw aesthetic. And Eureka beats them out in some ways.
Romance is one of my favorite genres and I consider Eureka Seven to be the best adventure romance of all time without much second thought. Not even sure what compares to it honestly. I'm giving it a 10.
