Temperatures
The cooling solution which graphics card vendors use is one of the main differences that consumers have to contend with. Apart from their acoustic properties, the thermal properties of graphics card coolers are extremely important. Lower temperatures are always better and with AMD and Nvidia opting to use dynamic overclocking algorithms that take temperature into account it is important that graphics card vendors use high performance cooling solutions in order to maximise performance. The era of graphics cards reaching dangerous temperatures are now in the past but the importance of lower temperatures still remains. Lower temperatures mean better stability, longer component longevity and lower fan speeds. That said temperatures are one of the most important non-performance related properties on a graphics card.
Find details of our temperature methodology on page 3.
at £125, it takes it into 7850 1gb territory, I concur with your conclusion, its certainly overpriced, and limited by that 128 bit bus width, for the same money you could get the 256 bit 7850 1gb, the memory throughput is so much better, and will allow the VRAM to be overclocked, SCAN has an MSI 7850 1gb for just £123.34, making this 2gb 7790 variant redundant.
http://www.scan.co.uk/products/1gb-msi-radeon-hd-7850-4800mhz-gddr5-28nm-gpu-860mhz-1024-cores-hdmi-2x-mdp-dl-dvi-i