Charging my in-ground sprinkler system
 

How important is it to "gently" charge my in ground sprinkler system
in the spring? When the guy came over to blow it out last fall, I
asked him how to charge it in the spring and was told to just open up
the valves. So last night I did just that. I turned on one of the
zones of my system, and then opened up all of the shutoff valves. All
of the heads are working fine, so it appears that all is well.
However, I was doing some reading today, and it seems that I was
supposed to only open up the valve part way, to reduce the water
pressure, as well as remove a sprinkler head from each zone in order
to let the air out. How important is it to do this? Am I safe as
long as all of my heads are working, or is there something else that
may have broken? Does everyone else use the "just turn it on method"
or do you all remove the heads and open the valves up part way until
the system is charge?