It's not so much speed, the athleticism level in MLS is pretty high, it's that his technical ability and game reading is miles above MLS level, where there are tons of defensive mistakes to feast on. It's much easier to ghost in behind defenders as he does so well.Despite losing a step Son is probably still lightning fast by MLS standards though.
Last season he was still wreaking havoc on Hoffenheims and Elfsborgs of the world, despite having a -much- more difficult time against better opposition.
I'd back Sonny to smash it in MLS, I feel like he fits the profile of guys who succeed over here. The travel burden won't faze somebody who's been jetting back and forth to Seoul his whole career.

