I double all the time and it helped me considerably once I got past the chop thing. It took about a solid year before I was comfortable going back and forth and it didn't hurt my sound and range. The air thing (long breath phrasing) was tough like Mother said, however, after some practice I'm able to "take in" a lot more air and phrase with it like I was playing the trumpet. It's all about providing a good foundation and not more air then you need to get the sound you want. That helped the trumpet side of things because now I have a lot more gas in the tank for the upper register stuff.

I think Boss had all that gas and more in the tank from day one. I bet he could blow out a candle from 50 feet away.