Direct CU II
Direct CU II means direct cooper, which means the copper heat pipes are directly touching the GPU instead of a copper base plate with the copper heatpipes running through. I don't think they are as good as the Twin Frozr. They have Direct CU heatsink on the 6970 and GTX 570 but it will take up 3 slots.
It is new marketing technique by Amd to sold their old 7000 series Gpu by re branding and New R series Gpu. The Hardware are as same same as capable of Direct X11.2 and openGL 4.3 as the 7000 series .
To sold this new Gpu's amd dont launch newer driver thats support Direct X11.2 for 7000 series. hence the R series are the only one who support Newer Direct X.
Direct CU II is not any new version of Direct X but just new way of cooling technique thats used by other gpu,s already but not specifically advertised by other Gpu's.
It is better to buy newer as they are come with good cooling not else if we compared to 7000 series gpu.
The 8000 series and 7000 series both have same performnce and other things 8000 is also re branding of 7000 series