Seeing that there is a huge lack of benchmarks for cards a few years old I decided to follow your lead! Here are my results for my GTX560TI SLI setup with a little cut and paste with my results added in and:
All at stock gpu clocks (880ghz), cpu is at 4.6ghz.
Batman: Arkham Origins: 47 (All settings set to max at my monitor's native resolution of 2560x1440, Vsync off)
Metro: Last Light: 44.67 FPS (1920x1080, DX11, Physx On, SSAA Off - AAA - DOF On)
After installing the new Geforce Experience and driver (337.50), followed by a reboot, I reran each benchmark.
Batman: Arkham Origins:47 (All settings set to max at my monitor's native resolution of 2560x1440, Vsync off)
Metro: Last Light: 44.67 (1920x1080, DX11, Physx On, SSAA Off - AAA - DOF On)
Absolutely no change for me in the final average results...however, in the min/max frame rates I did see a slight bump in the max frames recorded. Metro went from (min/max) 5/218 to 5/225 and Batman Origins went from 22/65 to 22/69.
Perhaps there would be a better increase in newer games? It seems that both of these title hardly needed a driver update, so minimal gains perhaps where to be expected...
I haven't tried Last Light (one of the many games in my Steam backlog), but for Arkham Origins, are you running it with all the DX11 features? I say this because they're very demanding and should probably only all be on if you're running a high-end card. Turning off even a couple would probably put you over the 60 mark. Did you check to see what GFE claims is the optimal setting?
My initial testing on my GTX 770 (non-Beta driver) was 60FPS (avg) with everything max, but with all DX11 turned off, it jumped up to 76FPS. Turning just the "snow" on, it dropped to 69FPS.
Obviously this won't impact the gains (or lack thereof) of the new driver, but just thought I'd mention it.