I admitt, i am a fan of the Russian historical series of the last decades. Being a history teacher, my interest can not be so surprising because I look for the answers offered by Russian cinematography to the provocative aspects of the country past.
Indeed, this series was one expected in high measure. And the answer is not bad at whole. It is unfair to compare it wijth other films on same theme because its purpose is very simple - a presumed confession of ivan Vasilievich using slices and crumbs of his reign and life in a critic moment.
1571 Crimean invasion against moscow is the frame odf story and it works just well.
The familiar high care for details, from buildings inn to the clothes is present. The romantized episodes of his life, like direct portraits of expressions of his madness/paranoia/manipulation are not missing.
It is a honest craft series, except , maybe, the not so fair conclusion, relativizing a reign not very comfortable in its last part.
But, sure, it is a series who use, in nice manner, subjectivity, not offering a hero but a man corrupted by his absolute power , discovering, in few hours, the monstruosity - root of his reign/survive/illusions/projects and offering not exactly a case but a good remind of neverending realities defining Russia power across the centuries.