update-manager vs apt-get

[Mario Vukelic]

On Mon, 2006-07-17 at 19:03 +0200, Ante Karamatić wrote:
> update-manager doesn't do anything special. It just removes additional
> manual work (editing sources.list).
> 
> So, command line would be:
> 
> sed -i -e "s/breezy/dapper/g" /etc/apt/sources.list
> apt-get update
> apt-get dist-upgrade

At the very least, it also does the equivalent of installing the
ubuntu-desktop package, I think

> So, as you can see, everything can be done from CLI.

I'd really like to get clarification about what the exact advantages of
update-manager are vs. the correct CLI way (incl. installing
ubuntu-desktop.)

There was a discussion on sounder a while ago about update-manager vs.
apt-get/aptitude for distro upgrades, where some people argued/demanded
that a simple dist-upgrade should be enough. Matt Zimmerman said things
that to me hinted to deeper differences  [1].

[1] https://lists.ubuntu.com/archives/sounder/2006-July/008080.html
    https://lists.ubuntu.com/archives/sounder/2006-July/008083.html

Also, it is often said that update-manager is "recommended", but the
upgrade instructions [2] contain language that suggests that both ways
(GUI vs. CLI) are equivalent

[2] https://help.ubuntu.com/community/DapperUpgrades

So my questions is, if the correct CLI way is followed as per the
instructions, what does update-manager different, if anything?