He isn't difficult but I always thought Nabokov (in his fairly incendiary reviews http://wmjas.wikidot.com/nabokov-s-recommendations) was on point that he was sentimental, preachy and mediocre as an artist.

I found Dostoyevsky a slog to get through and it might have been made worse because he was sold to me as this 'great psychologist' when psychological realism is often missing from his stories and characters become page-long megaphones for some version of Orthodox Russian nationalism or Christianity.

I think Nabokov definitely has a point with brothers. Ivan's portrayal and brain fever always struck me as a cop out because Dostoyevsky couldnt actually articulate what was wrong with his ideology. Of course thats kind of the point, but still it always felt cheap and clumsy to me