I've been trying out oUF again lately on beta and noticed a discrepancy between the oUF castbar and the azCastBar's safe zones. oUF always showed more latency than aCB. Attempting to move while in the oUF safe zone would cancel my cast, while moving during the aCB safe zone was fine. This may have been due to fluctuating latency on beta, but it was in Shattrath with hardly anyone around. Will keep an eye on it again tonight.