I didn't say he was full of shit, I'm saying anyone who makes the claim you quoted that 8 GB of DDR5 is "overkill" is full of shit. I'm not going to waste my time going to B3D to double check what you quoted and make sure you aren't taking it out of context.
Go take a look at industry reaction to the 8 GB of GDDR5 announcement. The foremost tech pushers (Carmack, Crytek guys, etc.) are all quite pleased with it. This is what they wanted. So why in the world would you put more stock in a quote from B3D than what the foremost professionals in this field are saying?
None of them think it's overkill. Most of them were saying that 8 GB of memory was just enough to meet their demands, and you can be sure they weren't talking about 8 GB of just DDR3. These guys are addicted to the GDDR5's bandwidth on modern graphics cards like a junkie is to crack. This is why MS is bending over backwards with their ESRAM "solution". 8 GB of GDDR5 isn't overkill, in fact I'd say for the first time in the history of the video games industry we're seeing a console that isn't being RAM starved from day one.