Speed set buff or nerf?

[Futumsh]

English is not my first language, but i think is pretty easy to understand that 'Base movement speed' refers to your normal speed (same you have when you start game). Now they changed description and it says 'doubled', which is basically same thing we had before but for ppl wiith serious problems in maths. Still some dont understand

-Your base movement speed is 100%. If you have 0% ms like some ppl say, you are a statue.
-'200% ms' and 'base ms doubled' are exactly same thing.
-From what i've tested, the only change i see referred to 'speed passive skills now stack' is that now we can use 5/5 speed passive while using speed sets.
-You are not slower now. In fact, you are faster if you use passive speed skill points.

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).