Beta drivers arent evil, they wont hurt your pc like say a virus would.
They are just beta because they arent yet completely tested with all popular games, so they could cause some odd glitches in games that have yet to be tested.
So install them and see if the TW2 runs better for you.
Then upgrade to new official drivers when they come out, since those will most likely contain the tweaks the beta drivers currently have.
If you have any funny glitches with other games that you didnt have before, just uninstall the beta drivers and install the latest official drivers.
No harm done.