You can obtain 100.00% taming effectiveness on x1. Your feed timing and quality of honey (time until expiration) is key here. I just tamed a 150 at 100% for level 225 on x1 official. Use a fishing pole, equip honey, then unequip and the honey refreshes its expectation timer giving you a fresh honey and rinse & repeat. I continually refresh about 6-8 of my honey in between feedings.
It may not make a difference...but to whom it may concern; you dont have to put the honey in your last slot...it can be in any slot. This might help those, who like me, have a broken right d-pad (xbox).