Sangeet Khatri :
I picked a Micro ATX case because it is what I prefer, it he likes he can change the case with a ATX case. It was just what I personally prefer.
The Seasonic 650W Semi Modular PSU was like 85 dollars and this XFX 750W Fully Modular PSU was like 89 dollars, so for just 4 dollars, there is no problem in having a much better PSU, so, i did not invested in a 750W PSU. It was just cheaply available, much cheaper than the 650W Fully Modular PSU's
What does he need more expansion slots for? Tell me anything other than a Wifi Adapter, most people do not really needs the expansion slots.
I am hundred percent sure than the 780 is much better than the overclocked 7970 and not just Marginally Better Performing as you said. The 780 is much better. The 780 is almost comparable to the Titan, the most powerful Single GPU card available.
There can be issues with SLI, but there would never be issues with a Single GPU card. Also two 760's in SLI is not equal to 780.
This build was not meant to be overclocking capable, that is why. Who said that every build should be overclocking capable? There is no strict rule on that. Is there??
Making an arguement for a modular PSU over a semi-Modular model for units under 750W is moot as all the non-modular cables will be in use 100% of the time if you are running a mid to high end GPU.
Here are the fixed cables of the XFX 650 semi-modular PSU:
1 x fixed 20+4pin Main Connector
1 x fixed 4+4pin ATX 12V/EPS 12V
2 x fixed 6+2pin PCI-E
Will your build be using all 4 of these cables? Of course it will. So what value does a fully modular PSU add? The XFX 650 semi-modular is $50 so there is a $40 difference in price for 100W capacity and a gold rating.
I brought up expansion slots because your board had no possibility of expansion to utilize the extra capacity of the PSU. You can talk about the merits of the 780 all you like but the reality is that the 7970 still provides the better performance per dollar. Also, there is a $15 difference between the 4670 and the 4670K. How are you going to claim "future proofing" and then not include overclocking capability if the motherboard supports it?
Lastly, bolding portions of your posts does not provide any more validity to your claims.