C2 is 2-3-3-6, that's why the site says so.

LL stands for low-latency, meaning 2-2-2-5. Lower latency means higher performance in most cases. CAS latency has long been the focus for most users when trying to get performance, but now that nearly all memory can handle that, the focus has shifted to the other timings. CAS latency is still the largest single factor for latency performance, the others can account for a few percent difference though. Whether it's worth the price increase is subjective. Plus, most 2-3-3-6 rated modules can run at 2-2-2-6 (even 2-2-2-5 should be 2-2-2-6 for best performance).