Re: Which is worse
> For Windows, that's including paging and hibernation files, but not for Ubuntu.
The 16 or 20 GB is the _free_ space required for an _update_ from Windows 7 or 8. The paging and hibernation files would already exist.
The 7GB is for a fresh installation and this would include the space required for swap file.
Ubuntu includes many applications and language systems, such as LibreOffice and Python, but not for Windows.
> It's even easier in Windows using add / remove features.
Ubuntu package manager also installs/removes thousands of applications, not merely 'features'.
> and can continue across reboots.
That is required because Windows _needs_ reboots. That is because Windows has a limitation that files that are in use cannot be deleted or replaced. Other systems have inode file systems that can delete and replace an open file, the open file continues using the inode until all programs close it. Thus, with *NIX, reboots are not required.