I
think Oleg was genuinely answering whether a hyper-threading processor (eg i7-2600K) would give any advantage over a non hyper-threading (eg i5-2500K)
[so to answer Feuerfalke - not all multi-core CPUs use hyper-threading]
His answer maybe reflects the results of some testing done by Custom PC mag when the Sandy Bridges came out:
in Crysis on their test system (DX10, 64-bit, 1680x1050, no AA)
i7-2600K
min fps = 36
average fps = 64
i5-2500K
min fps = 34
average fps = 60
There you have it - Crysis takes advantage of hyperthreading too,
'but not so much' 
(As others have remarked there is much confusion on the go over hyper-threading V multi-threading.)
...and just to confuse things further, when the 2 processors were overclocked the i5-2500K had higher min fps (42 V 37), and equal average fps to the i7-2600K (both 67). Apparently, hyper-threading doesn't respond so well to overclocking. Underlines the fact that things are more complicated than they may at first appear.
!!!
I went for the i5-2500K, but hey, it's your money
To be really safe wait another week and then check up on the feedback