Having suffered through solfege and too many "ear trains" to count, my ear didn't start getting better until people started handing me songs on tape and asking me to write charts for them.
I honestly just think that beyond the basics of knowing the intervals all the fancy ear training for ear training sake is kind of moot. Best ear training is just sitting a keyboard or using your instrument and trying to figure out either music you like or your own music that you are hearing in your head. Best way to learn intervals is just sit at a piano and sing along playing intervals.
When I first started to compose I was immediately struck with the reality that the music I heard in my head there were actually no notes on the western keyboard that would make it. I'd hear it in between pitches, intervals slightly off, etc.... Slowly over time just from trial an error I developed the ability to just sit in front of paper and write music w/o a keyboard in front of me. But that didn't come from ear training. It came from music theory and just working to get what I had in my head out into the world.