Memory suggestions?

I'm currently running 2x4GB G.Skill Ripjaws DDR3-1333 at a CAS of 9, and was wondering if I'd see much of an improvement if i changed to something in the 1866 to 1600 range maybe with a lower CAS? I cant go much higher than that though, my motherboard is a Gigabyte 970A-UD3 and I don't feel like spending all that cash to tear down and rebuild. I'm trying to get an idea of what to keep an eye out for in case it goes on sale in the next few days.

Thanks fellas. 

Don't you mean higher (longer latency)? 

I have 2x4gb corsair vengenace-1600 at 1066, 8-8-8-20 (rfc 86) with a core 2 duo e7300 at 1:2 ratio. When I tried 1600 mhz on memory and higher timings and FSB, I had about the same speed in games and wprime, but higher multiplier is unstable for me. 

There is not much benefit from higher frequencies on memories. DDR2 was more sensitive and i could feel a difference between my old 800 to 1066. DDR3 doesn't make much difference at least in games, but has more overclocking headroom, still too few memories can do over 1600 with under 9 cas, be careful, keep it cool.

Just saw your rig. Your AMD might be more sensible to clockspeed than intels, so go ahead and try.