When it comes to updating the operating system, the Windows Phone experience leans towards the positive when compared to the competition. Apple's iPhone notoriously need a huge heaping of space due to backups and Android, like all things, can vary from device to device.
However, one area that is of concern is Windows Phones with low internal memory. Even though some phones have a micro SD card for expansion, they can prove to be problematic for OS updates if there is not enough internal space. One minor fix in build 14219 of Windows Phone 8.1.1 aka Lumia Denim is the ability to install those updates using the expansion card.
Full story from the WindowsCentral blog...