Couldn't agree more. If you can take the pressure (which would come with consistent penalty practice) and you're able to strike the ball into the top corner, no keeper's saving them.
I can remember a few Ballack and Shearer penalties smashed into the TC where the keeper stood no chance.
I'm sure I remember some years ago seeing a documentary piece about one of the England Youth teams who were due to play in their Euro Championships. The coach at the time brought in a sports psychiatrist to talk to the team and had them go through some meditation exercises & had them visualise themselves scoring in a penalty shoot out. They did this several times in the build up to the tournament.
The ironic thing was, they won the Final beating the Germans on penalties.
Now it may have just been a huge coincidence, but it does make you think.