He starts to get annoying around minute 80, but fortunately that's when the movie ends

Kirk Honeycutt gets it right in The Hollywood Reporter:

The weapon wielded by Cohen and Charles is crudeness. People today, especially those in public life, can disguise prejudice in coded language and soft tones. Bigotry is ever so polite now. So the filmmakers mean to drag the beast out into the sunlight of brilliant satire and let everyone see the rotting, stinking, foul thing for what it is. When you laugh at something that is bad, it loses much of its power.

I don't know why Kazakhstan is so upset. It's the United States that comes off looking barbaric in Borat, which will be big at the B.O. Travers basically calls it a masterpiece. It's not, but it is duly outrageous, and coaxes the American people to reveal themselves as the backward wretches we truly are. In fact, it has the most outrageous scene I've ever experienced in movies. It's a lethal kind of comedy Cohen employs. He will be nominated for a Golden Globe.