This comparison is the first good news I found. I just entered the GPU model from my Retina 2015 MacBook Pro and the highest GPU option from the 2016 line-up.
I think, for a notebook, this looks pretty good, and it uses about 1/3 the energy of its desktop counterpart (Radeon RX 460).
A few spec comparisons to the 2015 GPU:
1. floating-point - 82% faster
2. texture mapping - 82% faster
3. texture mapping units - 60% more
4. shading units - 60% more
5. GPU memory - 100% more
Radeon Pro 460 (MacBook Pro) vs Radeon RX 460 (desktop):http://gpuboss.com/gpus/Radeon-RX-460-vs-Radeon-Pro-460
That's not as bad as everyone has made it out to be, right? Or, is it that the 2015 was just terrible?