Native speakers o English as teachers usually demonstrate good standard English, along side with idiomatic language and slang. An interesting turn of attention in the Russian audience has recently been towards authentic behaviour (gestures, exclamations, explaining everyday behaviour, e.g. how to wait in line "in the American way" etc.). In most cases, however, they miss the point that the learners and teachers in Russia need primarily the language of general use. Interest-arousing cases can't make up for the rest of the language needed and become a "sore" when they top out too much.