Hands up I'm not a 970 SLI owner but surely if you change your setup for a single 980 you will be getting worse performance in the majority of situations.
If the 980s had 6GB than sure in the long term they would pull more ahead but with effectively only an extra 0.5GB how many games will really fall into that sweet spot (between 3.5 and 4 GB used) where the single 980 will be better rather than just needing over 4GB where both 970 and 980 will suffer?
If the 980s had 6GB than sure in the long term they would pull more ahead but with effectively only an extra 0.5GB how many games will really fall into that sweet spot (between 3.5 and 4 GB used) where the single 980 will be better rather than just needing over 4GB where both 970 and 980 will suffer?