I currently use Simply Mepis 3.3 but have always liked the feel of Mandrake linux. One thing that stops me purchasing and installing it is its difficulty in installing Software. I have just downloaded version 10.2 rc2 in the hope things have improved over version 10.1 but again I find some applications i need are missing. One of them is the ability to use XFCE4 as a desktop. On Mepis I simply typed "apt-get install xfce4" & it was downloaded and installed to my login screen where I can select which desktop to use from a drop down selection box when I log in. I went to XFCE4's website which directed me to http://www.eslrahc.com/10.1/ where I downloaded and ran the file xfce-4.2.1-0.1010.3mdk.i586.rpm but during the install it just gave me an error.
When i rebooted mandrake it just logged me in automatically & took me to the desktop so I dissabled auto login but when i rebooted again the log in screen still did not offer a desktop selection box as in Mepis & despite selecting to install all the available desktops (KDE, Gnome, IceWM etc) during the install, I get no option to be able to select a desktop manager from a list at login as I do in Mepis.
Can you tell me if I am always going to have this problem installing other software & if I going to be able to install XFCE4 & select which desktop manger I want to use at login as I currently do in Mepis..

[personal opinion]
I would stick to mepis, or any debian based distro.

Mandrake is great for linux beginners, but as you have expirenced here, mandrake is not as easy anymore if you want to stray of the givven path.
[/personal opinion]

If you don't have your login set to graphical within the mandrake control center, logging out of kde will drop you into command line. If this is the case, "startx" will start your default desktop, you probably have it set to be kde. Command "kde" will start kde as well. "startx icewm" will start ice, "startx xfce4" will start xfce4. Set your login as "graphical" in mcc and logging out of kde will give you graphical login box with dropdown menu for all installed desktops where you can also change which is set as default. Another way is CTRL-ALT-F1 key combo, command "service dm stop" to shutdown X, then any of the above commands to start which ever desktop from command line. There are a few different ways to acheive same result.

As for easy installation of appz in Mandrake read this doc for urpmi:
http://speculation.org/garrick/urpmifaq.txt
Also check out the graphical software management tool rpm drake within Mandrake Control Center, doesn't get any easier than that, simple point, read info and click to install.
If you have not already done so, go here and set up your internet based sources first: http://easyurpmi.zarb.org/
xfce4 install is easy as typing "urpmi xfce4" in command line as root, or in rpmdrake by putting a checkmark in the xfce4 install box.

You need all the dependencies. I installed XFCE manually from there too.

Mandrake 10.2 is currently beta/testing software so things may not work as you desire. 10.1 would have been a better alternative.