Crimson Trace review
They (CT) work and they work well. There are two sets of Crimsom Trace grips in the family. They are not a replacement for learning the basics but they do have their place. My Mom who doesn't get to practice as much as I do, showed a bigger improvement with them than I did. But I did show an improvement with them in some circumstances. I am definitely not an uneducated or poor shooter.
The only negatives that I've seen is the cost. We have two. They are another tool that when learned and used properly are an asset.