When people here are talking about treating your room, they were talking about doing so to make the monitors sound as clean as they can in that room. Even though most of your recording is line in, you still listen to those speakers in that room. You are hearing a difference already; that ability to hear the separate instruments and their placement says a lot. I think your mixes will be improving as a result. I doubt you will be wanting to return to the old speakers..
Grow with the flow.

(Hey! I like the way that sounds. That may become a song .. grow with the flow)

I do not work here, but the benefits are still awesome
Make your sound your own!