I hear a lot of both older and younger men in my region of Turkey say it a lot. Oddly enough, it is only on either extreme and mostly by more conservative people. It would be a good sociolinguistics project I feel!
Well, yes and no. It is really better for a beginner to say all of the syllables as "i-yi-yim" however, Turks, much like everyone else in the world, do get lazy and like to run things together sometimes. :)