Hello,
As for why we have our own format solution, we will bring you some very important reasons:
1) As you already know, many of WordPress based websites are hosted in shared hostings that have small execution time limit for PHP scripts. We have figured out a way to surpass that issue thanks to our reloading mechanism, and that could not be possible if we didn’t have our own format.
2) Migration procedure is fully automated. Checkout all the other plugins and you’ll notice, that all of them ask you to enter find/replace pairs for migration. This solution surpasses all this steps and makes your life easier when you want to migrate your website without entering anything.
3) The zip format has limitations that we don’t have. For ex. zip file can not be larger than 4GB or have more than 65555 files.
And those aren’t the all reasons, but we think they are good enough to allow us create and use our own custom archive format. Also, I’d like to inform you that our SGBP Extractor is completely free to download and easy to use: https://backup-guard.com/downloads/. (although we believe that manual extraction is not necessary at all).
Regards,
Lisa Breen
BackupGuard, Support Team