Faster updates/upgrades

I found this on YouTube and I'm wondering what the drawbacks might be:

In the sources list he just replaces the second "http" in "deb http://http.kali.org/kali kali main non-free contrib" with "repo" (i.e. "deb http://repo.kali.org/kali kali main non-free contrib") and does the same with "deb-src http://http.kali.org/kali kali main non-free contrib". Would this cause it to download bleeding edge packages even though it doesn't specify that? Does it just change the source? It does seem to dramatically increase download speeds but I don't want to screw anything up. Thanks!