This is basically what we know of the new Maxwell series. Courtesy of Videocardz(if admins don't want it here, I can just do a custom table in Excel and post a picture here instead.)
The Firstrike Scores are as follows:
GTX 750 - 5 250 points
GTX 750 Ti - 5 963 points
GTX 650 Ti - 4 819 points
GTX 660 - 6 727 points
Given these specs, it seems like Maxwell isn't really that much faster than Kepler clock-for-clock but makes it up in energy savings, packing a lot more cores. This, together with 20 nm, should be the way forward.
I don't think there's really any disagreement on this point.
But where I do think there is debate is just how much better the 800-series will be, say the top-end card, compared to a 780 Ti in, say, Firestrike? 30% more? What's a reasonable estimate?

The Firstrike Scores are as follows:
GTX 750 - 5 250 points
GTX 750 Ti - 5 963 points
GTX 650 Ti - 4 819 points
GTX 660 - 6 727 points
Given these specs, it seems like Maxwell isn't really that much faster than Kepler clock-for-clock but makes it up in energy savings, packing a lot more cores. This, together with 20 nm, should be the way forward.
I don't think there's really any disagreement on this point.
But where I do think there is debate is just how much better the 800-series will be, say the top-end card, compared to a 780 Ti in, say, Firestrike? 30% more? What's a reasonable estimate?