The main thing I know about Milton is what Blake wrote.
The reason Milton wrote in fetters when he wrote of Angels & God, and at liberty when of Devils & Hell, is because he was a true Poet, and of the Devil's party without knowing it.
I thought this might be some subtle tendency, which Blake was clever enough to detect, but in fact it's completely blatant. Satan comes across as an heroic character, with brilliant speeches. As Raymond Chandler said in another context, it's enough to make a bishop kick a hole in a stained glass window.
What though the field be lost?
All is not lost; the unconquerable Will,
And study of revenge, immortal hate,
And courage never to submit or yield:
And what is else not to be overcome?
Hail horrours, hail
Infernal world, and thou profoundest Hell
Receive thy new Possessor: One who brings
A mind not to be chang'd by Place or Time.
The mind is its own place, and in it self
Can make a Heav'n of Hell, a Hell of Heav'n.
What matter where, if I be still the same,
And what I should be, all but less then he
Whom Thunder hath made greater?
Here at least
We shall be free.
Talk about wrong but wromantic! It may not come across in a short extract like this, but the whole thing is great.