I shot a M&P 9 last weekend and I would say they aren't as reliable as the G19.
So you shot one example of a gun model once, and in that brief encounter you were able to determine reliability for the entire model line?
Know the status of your weapon
Keep your muzzle oriented so that no one will be hurt if the firearm discharges
Keep your finger off the trigger until you have an adequate sight picture
Maintain situational awareness