I've used it 12 to 15 times a season for the past 3 or 4 years.
The batteries die very quickly. We work a VG/
VB doubleheader each night. We usually don't turn on the belt pack until we enter the floor. They'll last for two games if you do that. Two weeks ago, I arrived at the school and found the packs already turned on at 5:15pm. Girls game starts at 6pm. By the third qtr., myself and one partner were having problems. The console indicates when the batteries are low and the batteries were low in those two packs. So make sure you have fresh batteries.
Also, the mic needs to stay as close to the whistle as possible. You have to make sure that it doesn't slide down the lanyard from your whistle.
As for the mechanics, I use the NBA mechanics for starting the clock. I place my right hand on the button on the pack, and count with my left hand. Then I start the clock and chop with the left hand as i end the count. We aren't required to chop but I like the mechanic. It let's the timer and my partners know what's going on. As Bob said, multiple officials may start the clock when one of the officials is not used to using the equipment.
When we were just using it a couple of times a season, it was difficult to get used to the mechanics. But having used it so many times, it's not a problem anymore.