Good enough? Good enough!? Dude, this rig absolutely monsters the latest games and I haven't even overclocked it yet! The only change in this build was the mobo, the ASUS Z89 one that I bought originally seems to have been faulty, it was the cheapest one on eGay from a non trade seller but when I got it everything seemed 100% legit, perhaps just a dodgy mobo from the factory. Didn't recognise the CPU. For a moment I thought it was my CPU since the CPU was second hand, but from a quick Google it seems that mobos are far more likely to fail than CPUs. So that delayed the build by about 2 weeks which was frustrating. Anyway, said CPU is now happily powering the machine that I am typing this message on Got an MSI G55 mobo in the end, exactly the same spec as the ASUS one pretty much, Z87 chipset, overclocking friendly, Crossfire and SLI supported.
Edit: This is how thermal paste should look when correctly applied:
Edit: This is how thermal paste should look when correctly applied: