Originally Posted by
Futumsh
This is correct.
How things work: There are 2 types of speed buffs - multipliers and stats. Generally speaking, the smaller speed buffs are stats and the larger ones are multipliers. If you have a speed debuff, the debuff applies and the multiplier does not. If you don't have a debuff, your highest speed multiplier applies. Your speed is (unmodified character speed) * (evaluated multiplier) * (sum of speed stats).
So if you are not debuffed, have a speed set on (2x multiplier), and have 30% move speed from stats, your speed is (unmodified character speed) * 2 * 1.3.
The speed set description changed since people were confused by the old one, but its behavior did not change at all. The only speed related mechanics change is allowing the passive speed skills to stack (passive speed skills converted from multiplier to stats).