Re: What is better?
I'd go for the DDR3 1600. The only time that I would prefer a higher clock than timings is if you're overclocking. Raising your CPU speed also raises the RAM speed. 1600 MHz RAM would only limit you if you were to overclock over 4.4GHz (which is very unlikely).
My Desktop: Intel Core email@example.comGHz 1.39V Stable--ASUS P6X58D-E--6GB Supertalent Chrome (Elpida Hyper) 1800MHz 6-6-6-24--eVGA GTX 580--Intel 510 120GB--WD 2TB Caviar Black--Silverstone RV03-EK Supreme HF w/ Black Ice GTX 480--Koolance VID-NX580
My Laptop: Intel Core 2 Duo @ 2.4GHz--4GB DDR2 800MHz RAM--NVIDIA GeForce 8600M GT-320GB hard drive