I switched to Mold Breaker when it became clear that Hyper Cutter doesn't actually help against Intimidate, but I've always been wary of using it. After all, you get a good hit if you properly predict a Rotom switch-in, but if not, you're just using a weak attack while you spend a turn with lower defenses and you'll have to retain your low Speed on the next turn instead of getting rid of it that turn. It's such a risk, especially since with the lower Speed, you can't be as sure of outspeeding Rotom on the next turn if it survives.