According to what has been said by Matt Parnell, Axel with Apt-fast and can increase download speeds than 26 times.

This makes possible to shorten the time required for upgrades and installations.

To install Apt-fast you have only to execute from terminal:

sudo add-apt-repository ppa:tldm217/tahutek.net
sudo apt-get update
sudo apt-get install apt-fast

Once done,  what you have to know is that usage it’s the same of apt-get. To update database you have to run:

sudo apt-fast update

instead of:

sudo apt-get update

To install a package you have to execute:

sudo apt-fast install <package_name>

instead of

sudo apt-get install <package_name>

Also if you wanna make an upgrade you have to execute:

sudo apt-fast upgrade

or

sudo apt-fast dist-upgrade

instead of

sudo apt-get upgrade

sudo apt-get dist-upgrade

If you wanna delete cached download packages you have to execute:

sudo apt-fast clean

instead of

sudo apt-get clean

SOURCE: http://www.mattparnell.com

HOW TO USE APT-FAST WITH SYNAPTIC AND OTHER APT GUI

How suggested here you can use apt-fast also with all Apt interfaces applying a simple modification.

You have only to edit this file: ~/.bashrc

gedit ~/.bashrc

And you have to add after the last line:

alias apt-get="apt-fast"