Infused gives you bonus stats to the enchant on that item. So stamina gets more stamina, etc. Great for PvE because it allows you to be flexible in your character points and/or do more damage.
Impen gives you crit resist. Great for PvP because crit is where it's at in a lot of builds. Mobs in PvE (allegedly) don't crit.
PC NA Rayya Blackheart pitiful DPS NB CP160 PC NA Phaedra Phoenix beast mode Templar Healer CP160 PC NA lvl6 Mudcrab