The first thing anyone needs to know about HDMI cables is that they all have the same picture quality when UNDAMAGED.
Picture quality does not affect price because it is invariable, 1s and 0s do not change, it is the same principal with digital radio and why it is so much clearer.
You start with the base cable, the materials etc are minimal cost, so the first variable is build quality. Obviously one such as this is not going to have the build quality of a £30 piece of cable (at least you would hope the extra price would mean extra quality). All this quality does is to make the cable more capable to withstand wear and tear and extra forces applied to the actual cable.
Getting past these two, picture quality and build quality, what is left? Brand name. The only thing that largely separates a £25 cable and a £80 cable is brand name. There is only so far that build quality can go before getting into the highly unreasonable price wise.
As for this cable? The picture and audio, as I've already stated is invariable, and therefore is identical to that of the HDMI cable that was in the box with my XBOX 360 elite originally. The build quality on this product is not going to challenge that of even a £30 cable, but for the price is far better than I was expecting.
Rather than getting a "24k gold plated HDMI cable with plastic coating reinforced with weaved kevlar", or whatever bullcrap big companies want to churn out next for profit, I have a working HDMI cable, which does exactly what I want/need it to do. That's why it's 5 stars.