Hi Alley Oop,
I have been using SMXI for several years now and won't turn my PC on without it!! In all that time it only failed once to install a newer driver first go. At that time it also gave the solution which worked like a charm. If you can read what's on the screen then you can use SMXI. It's that simple.
There are just two things you need to know. The first time you use it to switch from the default drivers to Nvidia proprietory drivers you need to run it twice
. You run it once and then reboot. You'll get a message that X won't start. If it asks if you would like to try again just answer "No". This will leave you at a login prompt. So login as root and run SMXI again. When it's finished you can then let it start the desktop. This is the only
time you need to run it twice.
Secondly, if you get a kernel update or an Xserver-xorg update you will need to run it again and reinstall the Nvidia proprietory drivers. SMXI does not support DKMS so there is no automatic re-installation.
I used it just yesterday to update to 337.25.