What did you change, though? It's great that you're having a good experience now but the advice you've given to people who had your issues amounts to nothing more than "look at stuff in Nvidia Control Panel" and maybe change something related to VSync.
There are a bunch of settings in the control panel, if we don't know which ones to change, we could easily mess things up. If you go back into the control panel, the settings you changed, at least in 3D settings, will show up as bolded since they aren't the default settings. Which settings are bolded for you?
I haven't had a chance to get back to my Alpha, so I didn't want to mention anything specific without being able to look at what I changed.
Now again maybe this I just common knowledge stuff to tinker with for people, but I didn't know about doing this. So far it has improved the performance of games on my system. Not sure these are the best settings for everything, or if it will help others. But thought I would share in case that it might. I figure at least discussing it a bit couldn't hurt. If someone else knows more about this subject matter or has better recommended settings, please share.
The youtube video I watched about changing Nvidia Control Panel settings was this one:
https://www.youtube.com/watch?v=o8jeGVttFKI
So first off I changed:
Adjust image settings with Preview - Change to Performance side of the slider. And then clicked on the: Use advanced 3D image settings.
Then go into Manage 3D settings.
Switched off all the "A' lettered settings - Ambient Occlusion, Antisotropic filtering, Antialiasing, Antialiasing Gamma Correction, Antialising mode, Antialising setting, Antialiasing transparency.
Maximum pre-rendered frames - 1
Multi-Display/mixed GPU acceleration - Single display performance.
Texture Filtering - Quality - High performance.
Triple buffering - Off
Vertical Sync - I set to Adaptive. In the video, they turn it off.
I set Vsync to Adaptive and have been trying some games with in-game Vsync off and some games with in-game Vsync on. Not sure what works best for me yet. I think it might be on a game by game basis depending on things. If issues, lag, screen tearing do seem to happen, try turning in-game v-sync on or off and see what gets best results.
Edit: More info about adaptive v-sync:
https://www.youtube.com/watch?v=DAiPmazmR_M
Edit Edit:
Found some nifty sites that can test your V-sync in a browser:
http://www.vsynctester.com/
http://www.testufo.com/#test=framerates