Both depends on model
Power:
http://media.bestofmicro.com/U/N/352319/original/Power.png
TDP=/= Power Consumption
Temp:
http://media.bestofmicro.com/U/S/352324/original/Temp.png
HD 7870 is a good price is when its the priced the same as GTX 660 like in the United States and Europe. And, it comes with 2 free games. When, it is a lot more expensive then yea. GTX 660 wins
FXAA and TXAA blurs crap somethings and MSAA miss edges.
The extra boost does nothing at all when benchmarks already speak the truth.
Adaptive Vsync is pretty cool. AMD needs to integrate radeon pro into CCC.
HD 7870 embarrassed GTX 680 in computation. So, thats one very useful function GTX 660 fail to have.