It is extremely impressive technically speaking but I do think it was actually held back at times because it adheres so strictly to the metre. In its goal to “justify the ways of God to men” it fails on me, as I cannot justify any act of God by any logic presented to me. The story I loved,  and there are many memorable and important lines - Satan was of course the most interesting character. Adam and Eve are both held back by their staunch gender roles (I know this is silly to say) they were most interesting when they reached beyond what was expected of them and questioned God and their own reason for life (which of course they were punished for).