Thanks for the thoughts, Arctic.
Anyways, the reason I feel Magneton should have a SubSalac analysis is because due to the ridiculous amount of fast threats in the metagame, Magneton nearly does a better job than this than Magnezone due to its slightly higher Speed. I would definitely consider Magnezone if only it had just a few, and JUST a few more Speed points. However, it should be noted that Tornadus-T and Starmie still outruns Timid +1 Magnezone and revenge kills it with the appropriate move, while being outsped by Scarf Politoed is not a fun prospect at all.
Yes, Magnezone's Substitutes can survive Power Whips and Gyro Balls and Bullet Punches with impunity, while Magneton has a little less time to set up. I find it really, really annoying when Ferrothorn's Power Whips KO through anyways. However, in my experience, setting up boosts and consuming the Salac Berry is actually pretty easy, and will always result in Magneton either sweeping or weakening the opposing team enough for its fellow Water- or Dragon-type sweeper to come in.
Salac Magnezone can't really be ignored either, though IMO it's really annoying when you face random ScarfTars, and you can never kill Tornadus-T. I guess it's all about staying behind the substitute though.