The spin line of spells for enchanters are broken and people who play enchanters can exploit that game quite dramatically.
Using a lvl 9 spell, twurl to you hurl, or the upgrades, allows me to mez a mob and have them take dmg without it breaking. It never fails as long as it lands. I can have a lvl 10 kill anything tash can land on and the spin. The mob won't fight back and will die - every time.
When I play my chanter, there is no point to using mezz or it's upgrades, I use the ae stuns and the spins to lock rooms down because a 10 or 15 sec stun where the mobs cannot hit back and I can is better than sneezing and having mobs come too or non-fixed durations.
Just thought you should know, I suspect many people with chanters are using this bug.