I really liked this episode, thought it was classic Conchords with a lot of wackiness and silliness and clever puns and mix-ups.
I love how they self-deprecate with jokes about their own country's inadequacies and small-time stature first with Murray at the Consulate office from the 1970s, the Conchords themselves, and now with their Prime Minister "Brian", with the old style cell phone, the out-dated business cards with the last PM's name on them, and the White House not taking his visit seriously.
I thought the Jemaine side story with his Art Garfunkel psycho fan was hilariously ludicrous, and the impersonators really added some funny side characters. The Elton John impersonator was priceless, trying to claim another impersonator was impersonating him impersonating Elton John. I especially loved how they tied in the impersonators with the PM's meeting "the President". It really brought the episode together.
The weakest part of the episode was the songs, which I didn't really get into but got a laugh from. The Korean karaoke was weird.