There was a famous din Torah in which Reb Chaim and the Rogatchover both served as dayanim. The din Torah took a long time, and brought about many spirited debates between these two giants of Torah. On one particular occasion, the Rogatchover arrived to the Beis Din and said, “I have eight sources from the Yerushalmi that prove my opinion in this matter!” The Rogatchover was known far and wide for his phenomenal bekius, his absolute fluency in every corner of Torah writings. Reb Chaim, on the other hand, was known primarily for his piercing insight and power of analysis. Nevertheless, Reb Chaim immediately responded by addressing each one of the Rogatchover’s sources from the Yerushalmi; and how, according to his understanding, those Yerushalmis did not carry relevance to this case.
In reminiscing about this din Torah, Rav Chaim Ozer once said to my grandfather, “It is true that the Rogatchover’s mastery and fluency is simply untouchable. However, Reb Chaim’s analytical powers are such that he is able to deduce many fundamental conclusions from the words of the Rishonim that emerge because of the sheer depth and clarity of his iyun.”
(Related by Rav Moshe Twersky as heard from his grandfather, Rav Yosef Dov Soloveitchik)
I am nobody to comment on Rav Chaim Ozer's remark but if it is permitted I would like to add that the Rogochover was no slouch in his analytic capacities either. He just had a different way of looking at things than Rav Chaim did.