Mac OS X 10.9 Mavericks - install or wait?

It's always tempting to have a go with the latest software, specially if it's free as Mavericks is, from the App Store. Might be best to think about this one, though. A lot of people are identifying quite a few problems with Mavericks. There's a long list on the Apple discussion forums.

How to revert from Mavericks if you don't like it

Don't just rush and install it - I did :(  If you want to revert to your previous OS, the only way is to entirely erase the disk holding Mavericks and reinstall your previous operating system. So -

Before you install Mavericks -

• Back up your system and files - preferably use Time Machine.
• Make sure you've got a bootable install copy of your previous operating system. If you downloaded it it should be available in the Apple store > Purchases. But you'll still have to make a bootable install disk on a USB memory stick or on a disk partition.

Some problems people have found

I don't like to be negative but -
You can no longer sync your calendar and contacts straight onto your local computer. Instead you have to have an iCloud account and sync them via that. Many people strongly object to being required to allow Apple to store their personal information. http://bit.ly/1bsQEmg 

• Apparently, Apple have removed SyncServices from iTunes / Mavericks - permanently.
• If you want to continue syncing using iTunes in the future, it's said you should not install iTunes v 12 when it comes out (at the moment, it's 11.1.3).
• Many users are finding problems with Mail after installing Mavericks.
• Quite a few scanners and printers are no longer usable. Also, even more software than became unusable under Lion and Mountain Lion.
• Passwords seem to be forced to be saved on Keychain (I don't consciously use Keychain so I'm not sure what this entails)
• Mavericks offers finder windows that open in tabs, as in browsers. Personally, I don't like the tabs design (like Safari) and it mucks up TotalFinder, which I love using.
• Coloured Labels for files and folders have been changed to Tags - much smaller coloured disks: http://bit.ly/HSAnNk.

Altogether, best wait a bit I think.