There is a joke among Cirrus owners that the way to deploy the parachute is to pull it with your right hand, and then call your insurance agent with your left hand. The implication is that the aircraft is likely a total loss from that point.

Of the ~100 Cirrus parachute deployments to date, about 15 planes were repaired and put back into service. There were about 150 survivors and 1 fatality in those deployments. Cirrus says deployments have never failed when the system was being used within limits. I wasn't able to find the circumstances of that death, but the numbers show that yes, the parachutes are reliable.

As you point out, they can't protect you from whatever you land on -- lake, volcano, piranhas, etc.