[fainpul]

Yeah, "more slower" is indeed a weird way to phrase something. People should just refer to the absolute values, not to the differences. E.g. "1.4 times as fast as …" or "1/2 as heavy as …".

If I read "300% slower", I like to think about time, not speed.

300% more time = 400% original time = 4 times as long = 1/4 the speed

[degamad]

And that's where the confusion comes from: according to this, 300% faster refers to 300% more speed, whereas 300% slower refers to 300% more time.