I have the RS-1's and the 225's are very close to them, like some other models. The main difference is just refinement.
The 225's are an awesome phone for the money and I love mine. It puts you very deep into the music. I have the RS-1's but will not sell my 225's because they give me a different sound. They are a little more aggressive than the RS-1's but with 414's or flats, they are just right.
