http://www.anandtech.com/show/4061/amds-radeon-hd-6970-radeon-hd-6950/4
I did the math. Again it is a rough estimation, but GCN further improved on the efficiency that VLIW4 offered.
This is mainly why VLIW4 replaced VLIW5, AMD could remove 1ALU for every 5 they had and have roughly the same performance, so 160 cores would work out to 128, of course Wii U has 176gflops, those extra 16gflops would be further covered by the move from VLIW4 to GCN, which moved from 4alu groups to 16alu groups, allowing the 128 cores (alus) to handle multiple thread waves at once, think of it like a catch all, threads would feed into a wider bandwidth of processing than before, without changing the available number of cores, and since you could now do multiple instructions at once, you don't have to worry about ALUs going unused. VLIW4 to GCN was from a processing standpoint smaller than VLIW5 to VLIW4, hope you are satisfied with that, you can read more about it and anandtech is a great deep dive into VLIW4/5 and GCN if you search their archives. This is what the WUST thread did to me btw.
As for maxwell over GCN, I used ~28% better performance, in reality it can be as much as 40% but like I said this is a rough estimation on the safe side, I don't even add in the added functionalities like just being able to do certain effects better and more efficiently than R700's 2008 VLIW5 engine was capable of.
To everyone being down right dense, yes Zelda on docked Switch could do 1080p 60fps, it is straight up 4times as powerful, before feature enhancements , that is enough to handle the game at the higher demand, the only issue is that wii u's architecture is very different, while PS4, XB1 and Switch roughly have the same structure. IE a bad Wii U port can still run badly on Switch, while a bad ps4 port should be handled much better since PS4 and Switch are much more alike.