Yes, DAC's matter and you can improve the sound to your liking with proper selection. Some will give you a wider more open soundstage, some will tame harsh recordings, some will sound different, but not necessarily better. I would search this site for DAC reviews and conversations to help narrow the field. And since you are considering more musicality and less fatigue, you may want to look at R2R DAC's like MHDT Orchid and Audio Mirror Tubadour as well as many more. Pick a few based on user reviews, then buy used.
You are not loosing anything by using the Node as a streamer only, you are opening up new and possibly better sound.
Good Luck!