New CRISPR system that can switch single letters of the genome cleanly and efficiently

I (and few other members) already wrote about CRISPR, the revolutionary genome-editing technology, which is a very messy business. According to this article, scientists basically "whack the famed double helix with a molecular machete, often triggering the cell’s DNA repair machinery to make all sorts of unwanted changes to the genome beyond what they intended."
Now, researchers unveiled a significant improvement — a new CRISPR system that can switch single letters of the genome cleanly and efficiently, in a way that they say could reliably repair many disease-causing mutations.
If the CRISPR invention lives up to its promise — the experiments were done in cells in lab dishes, not whole animals or people — it could fix misspellings in DNA that cause Tay-Sachs, neurofibromatosis, sickle cell, cystic fibrosis, and other devastating inherited diseases, as well as mutations that raise the risk of diseases as common as cancer and Alzheimer’s.

https://www.statnews.com/2016/04/20/clever-crispr-advance-unveiled/

Paper: http://nature.com/articles/doi:10.1038/nature17946