One thing that has struck me whenever I've listened to YG and Magico is that they need to be listened to at "proper" volume to come alive. If you drop below that the energy drains from the music, which I suspect is due to the sealed-box design common to both.
Yes, you need a strong amp for both.
I find it amusing that people keep comparing YG and Magico as if they are in the same camp - i find them quite different sounding and believe @bonzo75 does as well.