My thing with Sentinels is that while loving them on paper, since I prefer to play range due to CoH's body collision which makes a full team and big spawns a bit of a pain to navigate in combat, the fact is that if I'm staying back and pewpewing then why not do it on a Corruptor and instead of flimsy defenses I'm throwing debuffs that increase my survivability anyway while also increasing mine and everyone's damage?
Especially since I happened to overhear one of the changes to anchors is that they keep on working even after the mob is dead, which is huuuuuge and one of the reasons I stopped playing /rad.