DDR3-2133 CL11 or DDR3-1600 cl9?

I don't care much about the price difference ($20) and I will use the system mostly for compiling and emulators (not games but things like qemu, android emulator, etc)

I will probably go with a i5 3570k

i'm now between a
Vengeance 8GB DDR3-2133 (PC3-17000) CL11 Desktop Memory Module Kit (Two 4GB Memory Modules)
and a
Vengeance 8GB DDR3-1600 (PC3-12800) CL9 Dual Channel Desktop Memory Kit (Two 4GB Memory Modules)

They are $60ish. ($55~70)

I'm also open to suggestions. I will probably not overclock the system as from my experience this is more trouble than it's worth (face it, overclock is not saving money, it's a hooby  


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edit, i'm trying to understand what CL means in real life... it's the amount of cycles wasted to get one row of data if I understood the FAQ correctly... so on one memory i will waste
9 cycles, from 1600/sec
so in one sec it has 1600 whatever-a-ram-does
i have to waste 9 to get data.
that translates to 177.7 data requests per second.

on the other
11 cycles, from 2133/sec
that gives me 193.9 data requests per second.

does this logic even makes sense?

it would be an ~8% increase, which is not seen here, at all, http://www.anandtech.com/show/4503/sandy-bridge-memory-...
those graphs show ~3% from DDR1600 to DDR2133. And they are comparing DDR2133 CL9! which should be even better.

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Q2:
Also i remember from a long time ago (when CL was called CAS) that cheap chips would have things like 2-2-6 and good chips would have something like 2-2-2, but both would be marketed as CAS-2

those Corsair chips are 9-9-9-24... does this mean CL9 is snakeoil for this brand?