I can't tell you how many times I have had to wipe off my cell phones, and if I did not have a backup, I would be VERY lost! Nowadays, so many people keep a lot of important information on their cell phones, so it is very important!
I have an iPhone and use both the iCloud backup AND sync it to my iTunes on my MacBook Pro at least once a month.
I do not backup my calendar, mail or contact to the Cloud because I use gmail, google calendar and google contacts, which have those items stored online already.
The best setting for contacts in google to sync without errors between your iPhone, iPad and online is to use CardDAV and ONLY CardDAV for contacts. The default settings on iPhone and iPad will have your contacts sync with main settings, but you need to turn those OFF and only use CardDAV. This prevents duplicates!
First go to Settings>Mail, Contacts, Calendars. For each account you have, turn OFF Contacts syncing.
Next create an account using CardDAV as the type of account.
User name: put in your full email address, including @gmail.com
Password: your email password
Description: Gmail CardDAV
Under Advanced settings, make sure "Use SSL" is turned on and the Port is 443.
Now, whenever you change, add or delete a contact (on any device), it will update it in all those places within a few minutes instead of making a duplicate!
For another safety setting, you should back up your contacts from google contacts at least every month or so.