No you will not notice a difference. you may see 1-2 FPS in some games. But none in even more. If you want most bang for buck get the memory with the best timings (IE: 7-7-7-15 is bettter the 9-9-9-18).
Toms did a DDR3 memory shootout http://www.tomshardware.com/reviews/ddr3-1333-speed-latency-shootout,1754.html
Check that out.
If you are going to overclock get the faster memory.