AlexisBeck
November 30, 2019
"Highly recommended"
Have been using Carbon Copy Cloner for several years without problems.
Have not yet switched to Catalina, so cannot comment on the other poster's difficulties.
In my experience, this app is the most well thought-through I have used, with a friendly, non-irritating screen interface which makes backups a cinch.
It is reasonably priced, they have been generous with upgrades, and the customer support is superb. Recently I contacted them with several questions, and received an email response _within 30 minutes_ which A) answered all my questions pleasantly and helpfully and B) referred me to links with detailed info on how to test backups to make certain they will work as necessary. This is in great contrast to the majority, where they happily tell you they have created a "ticket", and then you wait for weeks for a reply from someone who has not bothered to read (or obviously can't understand) your original question.
Highly recommended.