Its really hard to actually choose from both. Its like difference between 19 and 20. For some people Yuri is 20 , for some kiefer is 20. For me Yuri is better bcz idk why i see his efforts more than Kiefer. Not saying that Kiefer did nothing, but i somehow like the way Yuri looks and when he sulked, i found it a lil cute (i'm sorry).
But you know, everyone is so judgy and obsessed on how Yuri turns out to be a red flag in the book, but people do not understand the fact that this adaptation is somehow different from the book. It portrays Yuri much much much softer and more subtle.
SPOILER ALERT
For example, from what i've heard, in the book Yuri forces her to marry him and then gets into a relationship with Freya. But in the preview of next episode we can see that he just simply proposes jay jay and that even though they are having some company merge or partenership, jay jay looks happy while dancing with him which shows he's not forcing her and actually respecting her decision.