iLvl 55 item is no way stronger than PvE iLvl90, Unless the iLvl 90 PvE item has no Parry/Acc then it is stronger than iLvl70 PvE. iLvl 90 flat out beats everything even weapons vs Allagan version when Pentamelded. This is as far as my knowledge as a Rank 22 Marauder can give you. In fact I'd dare say most healer will go for Vit/Determination ring at iLvl 90 cause it is much better than the Healer Accessories available, for Tanks we use STR ones.

If at current stage you come in with full PvE iLvl90 I WILL eat you in 5 seconds flat no question upon CD pop. Not even requiring Full Swing.