Depends on what you do.
Most games don't really care too much about the CPU speed as long as it is fast enough not to slow down the graphics card. For games that do benefit from a faster CPU like Skyrim, then it depends on how may frame rates you are getting. The extra 300MHz is not going to be very dramatic.
A bit dated, but the following graphic does show Skyrim benefiting from a faster CPU.
However, if you are using CPU intensive programs like video encoding, then that extra 300MHz can help reduce the time it takes to encode videos.