At first I didnt really like them, but after going thru 2x weekend I loved them. While doing TMaps I was constantly getting them to spawn and was getting 50exp a hit off of them and they would stay alive for like 5minutes. Gained 2 talisman levels in like 10 hours of farming. Also gotten tons of halloween chests.
Just sucks that not all templates can deal with them and if you stick around a spawn too long youre eventually going to spawn them, then youre kinda forced to leave that spot if you cant deal with it.