Agree with that ^.
Movies, music or gaming, it doesn't matter... if your 3312 can cleanly drive your Klipsch set-up to your desired maximum volume levels, a separate power amp will not do anything for you. Unless you actually need the extra power provided by a separate power amp over what your 3312 can cleanly supply, there will be zero noticeable difference. Proper speaker placement and speaker interactions with the room and furnishings will totally swamp any "improvements" in audio quality promised by the purveyors of power amps.
Save your money for things that do make a tangible difference, like a sub upgrade or paying some attention to targeted room treatments. I would also strongly recommend you look into getting surrounds from the same Klipsch line to match your current front stage.