iOS 11 is finally available for download but that does not mean users should clamor to download the major update just yet.

While the update to Apple devices' operating system brings upgrades to the Camera and Photos apps, a smarter Siri and dozens of smaller new features like text drag and drop and emergency SOS, there are still several bugs that users should consider before downloading the update.

First, there is the download time. It will not be a surprise if thousands of Apple fans will all be downloading iOS 11 at the same time during the first few days of the OS launch. Download speeds will definitely be affected, meaning it might take users longer than expected if they choose to download iOS 11 right away.

The total download size of the update is 2 GB. Users should also make sure there is enough space on their device before trying to upgrade.

Of course, it is also expected that every major update comes with bugs. The last Apple OS release, the iOS 10, left some users' iPhones frozen. This resulted in users opting to reset their phones entirely, with large amounts of valuable data lost.

Previously, iOS 8 also left iPhones non-functional. While the iOS 8.0.1 update fixed that specific bug, it also left smartphones unable to connect to their cellular networks and logged in reports of Touch ID errors.

That being said, it might be wise if users decide to wait for reviews before updating their phones.

It is also important to note that not all Apple devices are compatible with the update. Users can determine if their devices support iOS 11 by checking Settings > General > Software Update. If there is an option to upgrade to iOS 11, then the device is sure to support the update.

For reference, the list of iPhones compatible with iOS 11 include:

• iPhone 8 and iPhone 8 Plus
• iPhone 7 and iPhone 7 Plus
• iPhone 6s and iPhone 6s Plus
• iPhone 6, iPhone 6 Plus
• iPhone SE
• iPhone 5s

Users are advised to backup all their existing data and charge their phones before attempting the upgrade.

It might also be wiser to download the update on a laptop or computer and then updating the smartphone via lightning cable to avoid download errors on users' iPhone devices.