On the note of macho brace ferrothorn, I don't think Ferrothorn needs to further lower its speed. Looking at the speed tiers (http://www.smogon.com/bw/articles/ouspeed_tiers
) everything faster than Gliscor's speed tier gets hit with a max power Gyroball. Adding machobrace only changes that to about Conkeldurr's speed tier. The only pokemon I could ever see being really harmed by macho brace that aren't already are: Scrafty, Xatu, Roserade, Venusuar out of the sun, Toxicroak, Machamp, Blissey and Chansey, and Conkeldurr. None of these are top 20 pokemon, and half of these are pokemon you could beat normally, and the other half you have no business staying in on.