For a long time, I've been extraordinarily happy with both NVIDIA graphics hardware and the vendor-supplied binary drivers. Functionality, stability, speed. However, things are changing and I'm frustrated. Let me tell you why.
Part of my job is to do teaching and presentations. I have a trusty thinkpad with a VGA output which can in principle supply about every projector with a decent signal. Most of these projectors do not display the native 1920x1200 resolution of the built-in display. This means, if you configure the second display to clone the first, you will end up seeing only part of the screen. In the past, I solved this by using nvidia-settings and setting the display to a lower resolution supported by the projector (nvidia-settings told me which ones I could use) and then let it clone things. Not so elegant, but everything worked fine- and this amount of fiddling is still something that can be done in the front of a seminar room while someone is introducing you and the audience gets impatient.
Now consider my surprise when suddenly after a driver upgrade the built-in display was completely glued to the native resolution. Only setting possible - 1920x1200. The first time I saw that I was completely clueless what to do; starting the talk took a bit longer than expected. A simple, but completely crazy solution exists; disable the built-in display and only enable the projector output. Then your X session is displayed there and resized accordingly. You'll have to look at the silver screen while talking, but that's not such a problem. A bigger pain actually is that you may have to leave the podium in a hurry and then have no video output at all...
Now, googling. Obviously a lot of other people have the same problem as well. Hacks like this one just don't work, I've ended up with nice random screen distortions. Here's a thread on the nvidia devtalk forum from where I can quote, "The way it works now is more "correct" than the old behavior, but what
the user sees is that the old way worked and the new does not." It seems like now nVidia expects that each application handles any mode switching internally. My usecase does not even exist from their point of view. Here's another thread, and in general users are not happy about it.
Finally, I found this link where the following reply is given: "The driver supports all of the scaling features that older drivers did,
it's just that nvidia-settings hasn't yet been updated to make it easy
to configure those scaling modes from the GUI." Just great.
Gentlemen, this is a serious annoyance. Please fix it. Soon. Not everyone is willing to read up on xrandr command line options and fiddle with ViewPortIn, ViewPortOut, MetaModes and other technical stuff. Especially while the audience is waiting.