Quote from: TeaLeaf;378667I don't think the card differential is anything like that much in the UK market, AMD & nVidia are broadly similar at the major price points as far as I can tell.
The K is always a recommended option as it is almost an identical price, there's £10 difference between having the option to overclock and not, so people tend to err towards a K processor when there's the option especially as the screening will have pre-selected a better bit of silicon which should also run better at stock speeds.
AMD 290X is around £430 and gets around 7000 points in benchmarks, a GTX 780 is around £420 and gets around 8000 in the benchmarks. So at the high end price point, there's not much in the way of competition. On the lower rungs it the picture is better for AMD, but they have been struggling to keep up in recent years.
As for unlocked CPU, I buy pre-overclocked ones for exactly that reason. They put them on a bench and stress test the CPU. If it's unstable when overclocked it goes into another machine and they keep going till they find one that works. I'm sure the majority of CPUs work, but the price difference is so low compared to the amount I spend of the whole system that I doubt I'd go back to buying off the shelf and crossing my fingers.