Two of the absolute worst breakers I ever had to deal with -
First, a big, precociously developed, agressive TB colt. His previous handler was afraid of him, so she just lunged him. A LOT. In deep sand. For 30 - 45 minutes at a time. So when I got him, he was unbroken, rank and really, really fit.
Second was a big, precocious developed, very sensitive TB colt. Bright chestnut and the type who's skin crawled when you touched him. Previous handler was afraid of him (and got hurt on him) so she tiptoed around him and accomadated his sensitive nature, to the point he would spook and bolt if the stirrup banged his side. Desensitizing him and teaching him to just cope and be a horse was a nightmare. He spooked and bolted across the track and tried to jump the gate the first time he saw the trainer standing in the tower.
Give me something unhandled any time.