Henadic Theologian
Legend
Not a fan of halo's personally, as they inherently imply a 'high magic' setting. Horns can easily appear 'down to earth' and low magic in appearance. But a glowing magical circle just permanently hovering around is something which just doesn't fit in a low magic campaign.
I'm fine with them being an option for aasimar, but I wouldn't want it forced onto all of them.
(though for the default PHB art, I think one with a halo would be a good idea, as it clearly displays what they are and sets them apart).
That is why I think glowing eyes is a more subtle way of doing something akin to Halos, indicting this is a being of light.