Very nice, and I concur. Apathy has the quality of being turned off to the world, shutting it out perhaps. Awareness of impermanence, and balancing your desire seems to bring a refreshing clarity, an elevated conciousness— and it is one with equanimity in it.
I understand the feeling. My experience has been to use my feelings to distinguish between the 2. Apathy to me feels negative and heavy and it suggests to me that I'm still attached but in a negative way. I guess another way to say it is that for me, apathy = stealth attachments that have gone under the radar.
Being non-attached feels more neutral or having a quality of equanimity to it. It is not heavy or light, not negative or positive, it just is as it is where it is.