Well done Rated 5 out of 5 stars
I've been using this for a while. I usually use private tabs when I want to have two different profiles, for example, login to two different accounts simultaneously.
It works great and I have never had problems with it. The developers also took care of downloads, when I try to download something on a private tab and then I quit it, it gives an alert message and also allows you to open an empty private tab to continue download.