You should just be able to do an I'm just installing this image myself currently, planning on replacing gdm as well as doing the rest of the optimizations found on that page.

Edit: Having my own problems now though. When it tries to update Mono I end up with

I tried to do what you said, but the problem is that I get the same error as when I just try to update. Basically, I need to fix that error somehow, because otherwise it looks like I can't install anything.
Maybe I should just deinstall 'xserver-xorg-video-trident' and then try to install it again, but I want to be sure that it's going to be OK.

As about your error, I think I never got that one, so I don't know how to fix it :(

Today I sat down and finally fixed the problem.

If you are getting the same error as I had, here is the fix:

You need to go to var/lib/dpkg/info using your console. Then you need to remove the package lists that are causing the error. You can do this by executing "sudo rm nameofpackage.list". In my case, after removing the first list, when I tried to upgrade, another problematic list appeared. So you need to keep removing all those lists until you get rid of all lists that have problems.

Now, after doing this it is better to restore those lists. You can do this by reinstalling the package and you can do this by executing "sudo apt-get install --reinstall nameofpackage". It will just reinstall the package and restore the correct list without doing anything else. If you won't do this it will always inform you about missing lists. You can reinstall those packages after doing upgrade too, if you prefer it that way.

After fixing this error I installed xfce4 following the instructions in wiki. Now I'm writing from it. To be fair, I'm not sure if it's really worth it. It's faster, but it's not significantly faster compared to GNOME and it looks kind of different from the look of xfce I have on my linux mint install.

Also I'm not sure how xfce power manager is supposed to work with another power manager from GNOME. It doesn't have controls for screen brightness, so I have to manually execute GNOME power manager and that one applies correct settings.
Can anyone tell me how I can turn off xfce power manager and make GNOME power manager to startup automatically?

Overall, everything else seems to work fine. Oh, the sound question... When I tried to configure sound volume it nearly killed my earphones. I set it like to 50% and it was just too loud. Now it's on 30% or something, so be careful with this.

The keyboard controls do not work by the way, if anyone knows how to fix that, please explain :)

the xfce mixer doesn't quite work right on the efika for various reasons. I don't have the details in my head at the moment though, but I do remember I had to tweak a gconf setting to make gnome do the right thing.

as far as the other problem it sounds like the package database got corrupted somehow. no idea how that happened.

I see. Well, after using xfce a bit, I think it's pretty usable, so I decided to keep it instead of GNOME.
That said, I would appreciate any advice on how I can improve my experience :)