Is celestial armor any good?
Hmm, for example it’s considered OP in conjunction with Elementalist and Engineer
For PvP/WvW roaming of course
Three major things to look for:
1.) Do you have a lot of hybrid attacks? Ones that have good power damage and a secondary condition applied on hit.
2.) Do you have access to more than just your heal skill for healing? Can you really use the healing power stat effectively?
3.) Can you stack boons like might on yourself reliably?
If you can answer yes to these questions, then chances are celestial is a reasonable option to consider. This is why Engineers, Elementalists, Warriors, and, to a lesser extent, Thieves make good use of it.