Is there an idiomatic equivalent of "I really loved what you said"?

How about "You took the words out of my mouth"?

WARNING: This answer is for mature audiences. Reader discretion is advised.

I think JBanana comes closest to the intent of your idiom, at least as you express it in English. (I would add "right," however, as in "You took the words right out of my mouth.")

To get closer to the poetry of the original would require, well, poetry; and in post-ironic America, at least, flowery or sentimental language is likely to produce unintended consequences, not the least of which is that someone in the group would feel obliged to make a joke about it.

I would probably say something like, "I couldn't agree more." That is much less poetic, but sums up the feeling.

That said, there are some slangy expressions that might hit at the heart of what you are trying to get across, though in different ways.

Young people in the last dozen or so years who are influenced by hip-hop culture might simply say, "Word!"

Older people (in informal situations and among friends) might say "Fuckin' A!" or "Fuckin' A right!" to expression strong agreement and emotional solidarity.

You might say "I couldn't have said it better."

"You spoke beautifully" is pretty common. It can refer to both eloquence and ideas.