It's clear that Itachi is the superior combatant. He is even more intelligent and skilled, both feat wise and according to the databook.
There is no progress of Kakashi. His skills were inferior to Itachi in pt. 2 according to databook and feats, but people thing that Kakashi made a bigger progress from pt. 2 to the war than from pt.1 to pt.2, what would be 2-3 years of training. His only progress was Kamui during pt.2.
People are confused, they take the short fight of Kakashi and his team against a clone of Itachi with 30% of his strength, who merely tried to hold them back from the Akatsuki hideout, as a measurement for Itachi's full power and think that Kakashi is superior to Itachi's skills as he managed to make one Bunshin feint to counter Genjutsu. As if Itachi couldn't use feints, Kagebunshin, doesn't possess insane speed and strong Genjutsu, which he can cast on various ways. If people actually debate whether Kakashi is more skilled, they skipped through Itachi's moments.
And yeah, Kakashi has one Mangekyo technique which is Kamui, Itachi has 3; Amaterasu, Tsukuyomi and Susanoo.
Stop debating with this Dimitri, he only talks BS.