I've ran Mobil 1 5w30 for a LOT of hours (and years) in my big CH without a single issue, in any temperature from 100*F to -25*F. I think I've changed it once in all those years...it was the second fill after about a 30 minute break-in.
I recent changed the oil in my generic pancake compressor (it wouldn't start below 40*F) to 5w20 Mobil 1 (hey, its a cheap experiment) and it not only starts faster, it recovers quicker and runs cooler too! It was a very notable improvement.
I could understand the "additives in regular motor oil can cause valve deposits and reduce pump life" if we were talking about an oil from 1955, but aren't today's oils are specifically made to not leave deposits?