The N810 amp is quite horrible. With low-impedeance headphones the noise floor is right up there in the music, almost as bad as the noise introduced by headphones with active noise canceling.

In-ear phones, like for example CX500 mentioned, really transformed the listening experience for me, but the sound quality depends entirely on getting a good seal. Without a good seal, it will sound tinny and rubbish, and you might reach for the volume control and turn it up. Also, having an airtight rubber thing jammed into your earcanal is something not everyone can get used to