Sure i rolled back to 344.75 to from the new 347... version. I wanted Elite to work with DK2, so that's the way to go at the moment. I've read somewhere something about that Elite developers and Nvidia are aware of this problem and trying to look into it.
And - it's not like every newest driver will bring your graphic card to new heights and performances. Sometimes there are just little things or just special things that get fixed or implemented, optimised, whatever. But that doesn't mean, you will notice it right that same moment. PCs can be quite complex in reaction, depending on the overall sytem and hardware components working together. When there are people noticing something better running or working on their system, doesn't mean, it will be the same for other PC owners.
Example: one system can run a game or program without problems after a new patch gets released - another system crashes the game or program after installing the exact same patch - you read this all the time at game releases, patches and so on.
So - the next newest driver doesn't have to be the best for your system or your game, because it's newer then the old.
I for myself usually wait for another two or three versions later, where it's established, those are working properly ... sure i've tried my luck with version 347... but it didn't work with Elite and DK2 - so back to 344.75 .