But I thing silveforce is trying to say that when you have hot room if you are living in hot climate or no proper airflow, the OC ability goes out of the windows from the get go. And like you RS have so many times pointed those intel graphs which prove that when silicon is running hot it is also using more power. Also affecting even more to the OC ability and making the whole system use more and the room hotter.
Second point, I have my computer under the office table on my left side where I sit and the table is placed against the wall from right side and from front. So there is only one way the air comes out first and its mostly just where I sit between me and the table. All the hot air comes straight to my face and the difference is pretty big when gaming and when not. I have 7970 OC to 1.1GHz and sometimes while gaming the hot air is really annoying. Any more than that in in my face would be really annoying all the time. While 40-50w is not much in total system power and not really much warming the room, but straight in your face it is starting to be a big deal. So I think that is also one of the things silverforce was trying to imply. The new PSU for every new GPU is starting to become really old excuse and it's hard to believe that all those 550$ 980 owners doesn't invest in other components of their systems like PSU. Besides mostly everybody any time someone is asking what PSU to buy is suggesting something good and efficient which doesn't take the whole system with it when it goes poof.
Great post, as with a lot of things YMMV and if 40-50W of GPU power usage actually results in that much heat being exhausted directly at you, I can see how it's a big deal. Also, for some people they feel more environmentally conscious if they are buying a part that they know uses less power and are willing to pay extra for that. I personally don't get that since there are plenty of other electronic devices or buying a more fuel efficient vehicle that can be used to target that desire but again YMMV.
I just think in the last 3 years the constant movement to perf/watt from users who overclock their CPUs and GPUs is becoming really hypocritical. If someone really cares about perf/watt, they aren't buying i5/i7 K series CPUs and game at 120-144Hz where the GPU uses even more power. It's like this idea of picking of choosing when perf/watt matters and when it doesn't is what leads to this debate. For example, if we go with the idea that YES, perf/watt matters, then I'll go with the idea that 60Hz gaming is more than good enough and those who are gaming at 120-144Hz are wasting electricity and are harming the environment -- and you know that would be a ludicrous argument. Also, if 40-50W power differences matters that much, how did a lot of these same people who are making such a big deal used GPUs in the past, especially Fermis and overclocked GTX460s!