Don't build without it. Moving from Localhost? Moving TO localhost? Cloning sites? Routine backups? CRON'd backups to your s3 storage?
You cannot beat this extension, this support and this quality.
There are 6 extensions that go into every single site I build. This is one of them. Client says "I have a backup system", I say "that's great" and install Akeeba. Its fast, effective, bundled restoration and just handles EVERYTHING.
There are a HANDFUL of extensions I don't leave home without - maybe 6 all up. This is one of them (although I use admin tools pro lately!). Another in that list is Akeeba Backup, by the same developer. Admin Tools and Akeeba go into every site I build, without question.
Consistent across platforms: check
Well documented: check (seriously well documented.)
Support: triple check
Nick routinely assists people with major site issues even though they are nothing to do with his extensions. The level of support is amazing.
Not only that, the self service documentation and trouble shooters are superb.
Product updates are constant and the extension does exactly what it says it does. I put up 2 test sites with Admin Tools "just to see" one day - they averaged 15 hack and probe attempts PER DAY for 3 weeks.
Get admin tools. Secure yourself. Make it easier to manage websites. And get back to the fun stuff, like building websites...instead of screwing around with security.