Doesn't really matter glyphed or unglyphed, the throughput just isn't there since it's not adding as much from Earthliving. It's not really needed most of the time either; all 3 healers help on AoE healing with their (mostly) passive abilities like Healing Rain, Wild Growth, Holy Radiance etc. You're typically better off using single-target heals to pick up the few that are lower than the pack and letting those passive heals take care of the rest.
As for WotLK, that depended quite heavily on the encounter. BQ, Sindragosa and Putricide all required heavy use of CH for example, even in 10m. Other fights, not so much. It had a place in almost every fight though, if only temporarily so.