Using Outlook for iOS for personal email and calendar management
I have not tried a back of the device, we did make them just in case, but didn't restore as everything we do is hosted in the cloud or making calls to one of our database servers.
The difference in the reset is that it just wipes out the user information, installed apps, and reboots to start over. More like creating a new profile on a desktop vs reinstalling. The recovery from iTunes however, downloads the complete image clean from Apple, iOS, the firmware, etc. It does a hash check at download and unpack, then does another verification after it install the firmware and iOS.
The way I understand the iOS back up with iTunes is that it saves all your preferences and files, NOT the apps. You will see the little down arrow on the icons, tap on that and it will redownload the apps to complete the install. Outlook should only retain its settings. It will redownload any emails based on your preferences. We tend to only store 1 weeks worth on the devices but allow the user to adjust based on their needs.
We do not have any other reported slowness issues to test this approach though.