I introduced the "Sweet Bells" version of the carol to our primary school as an individual item for a district carol concert about 6 years ago. Since then we have only ever sung that version. It is loved by everyone.
This year we are having a Christmas "sing-along" with the parents, and many parents have asked that it be included.
The year 5 and 6 see it as a "rite of passage" nowadays to sing the "echo".