Back when the otto box was first released, I buyed one for the pet (sue me), and used the stone to get myself an instant cannith challenge runner. Later that week people told me that I could use the XP bonus to skip more levels. My thought at that moment was not "Bummer, I could have saved time in a TR life", but "This is a weird bug".
I still think the XP stacking is a bug. So, I expected that sooner or later that would stop working, and the stones would really put people at level 16 as intended.
So, yeah. Cry me a river.