When AMD began releasing their DirectX 11 capable GPUs they began with the 5000 series, soon after ending up with a complete top to bottom product family which could make use of the latest DX features. For the 6000 series things haven't quite happened as fast though and to date we have seen 6800 and 6900 series GPUs hit the market with the 5700 and below filling up the lower end of the product stack. In terms of pricing this has created a gap at around £120/$150 which has yet to be filled by a new product, though the 5800's do a reasonable job in this area.