The transition can be very easy. Do you have "Back up to iCloud" selected under the Summary tab for your iPhone sync preferences with iTunes?
When backing up locally on your computer's hard drive, the backup is updated as the first step during the iTunes sync process. The same applies with Windoze iTunes, and with iTunes on a Mac.
You can manually backup without having to sync by Control-clicking on the iPhone under Devices in the iTunes source list vs right-click on the iPhone with Windoze.