Do you really care, whether the customs and immigration officers are friendly and give you a nice welcome?
I suppose, most of you travel so much that they know the typical questions (and the best answers) and shouldn't really bother.

For me one thing is relevant: TIME
On my last arrival in the US I spent more than one hour in the immigration line, even if I was travelling in C and was the first to exit the aircraft. In SVO I once lost half day due to problems with my visa.
That makes me angry, even if the officer were very friendly - in SVO they weren't at all...

With regard to the time my experiences in the US an varying (LAX consistently good), in
Russia bad etc.
In my home "country" europe I only have rarely longer lines (>10min) at immigration.