User blog comment:Alartan/Swiftness or Mobility boots?/@comment-4843720-20150202011710/@comment-24590723-20150205221627

I used to buy Swiftness for Sejuani, but since some time I rush mobility. I liked to overtake my enemies in death races:)

But anyway, that slow reduction is not that big in values. That's due to soft caps in movement modificators, slows are the most efficient in low values, Tresh's r isn't snare and it's not that much better than Nasus' Wither.

If slow reduces you ms by 100, after reduction it will make you slower 70-80. Anyway, I find that passive just additional profit.