While I agree with some of your observations, there will still be widespread use of x86 OS's for years into the forseeable future for various reasons (mostly application and hardware compatibility). So while x64 OS's have their benefits, currently its use doesn't fit all consumer's needs, nor do all consumers need a x64 OS. This is a transitionary period, much like back in 1995 when Windows 95 became the first psuedo-32-bit OS. Did everyone immediately format their HD's and throw their Windows 3.11 floppies away and install Windows 95? No. It took years for that to happen and it didn't really come full circle until Windows XP hit the market (a true 32-bit OS). Even then, there were still DOS and 16-bit Windows programs available and in use. The same will happen here. x64 programs will eventually proliferate and force the market (and thus individuals and businesses) to get on the x64 band wagon. It'll just take some time.
The only point on that list that is relevant is "Better driver support" and that doesn't matter for current consumer-grade hardware (As there are very very little pieces of hardware that absolutely cannot work under x64 Windows).
You obviously don't work in IT - if you did you'd know how much of a deal-breaker this is. Yes, hardware currently sold in stores have x64 drivers but there are plenty of people (and companies) with legacy hardware and software that won't work in an x64 environment. And not everyone who buys a new PC with an x64 OS will immediately buy all new software/peripherals to go with it. Why? Because they expect all of their current software/hardware to work on the x64 OS and it won't. I deal with this everyday in my IT job where I do just that - replace old WinXP computers with new ones when they reach 3-5 years old. New PC's coming in have WIndows 7 x64 and we have to step many of them down to x86 since many older programs and peripherals (even a 3 year old HP All-In-One printer, for example) won't work properly on the x64 OS. Why should we have to replace ALL of our hardware just to use an x64 OS? That would be fiscally irresponsible.
Less overhead? I dunno, according to process explorer, my current Windows 8 install uses somewhere around 300MB of memory by itself. Not sure if that qualifies as "more overhead" compared to x86 code.
Check minimum system req's for Windows 7/8. x64 requires double the amount of RAM. Coincidence? Hardly. Sure it can USE more memory space but it also requires more memory space to function at its best. And more RAM means more cost.
Another benefit to using x64 Operating Systems is that they can use the extra memory to cache all sorts of stuff, improving system responsiveness in the process.
Let me repeat: There is, at this time, no longer any real benefit to using an x86 OS for a normal consumer (Not that you can actually get one if you buy a new PC at this point).
32-bit OS's do the same thing with its usable RAM supply. If you're not running CAD or GIS or Adobe Creative Suites with huge data files you're not even scratching the surface of a 4GB RAM supply. So now, add a x64 OS and another 4GB of RAM and use it with the same everyday consumer software (MS Office and such) and where is the benefit? Sure you can open every program in Windows twice along with every other app installed on the PC and you still won't get close to using up all of the 8GB in the x64 system. So why do it? Just because you can? Again, not everyone needs a x64 OS.
And yes there IS a benefit - that benefit is better application and hardware compatibility/support. Maybe you have the money to replace every app and peripheral in your house when you upgrade to an x64 OS, but the rest of us mortals want to be sure all their stuff at home will work with Windows 7/8, and using an x86 OS will increase that chance of success. Ever try to run a DOS or 16-bit app on an x64 OS (without DOSBOX)? Denied. On an x86 platform they work just fine.
This isn't true anymore. The only benefit to FirePro cards and their drivers is that AMD certifies them for use with certain professional applications, like 3DS MAX, Maya, AutoCAD and the like. On an API/Performance level, they are no different to consumer cards.
I disagree. Yes, nVidia and AMD include ultra-optimized drivers for specific programs so those app can perform exceptionally well on their workstation-class video cards. It's a known fact that the OpenGL drivers included with workstation-class video cards are far more optimized/streamlined than the OpenGL drivers included with consumer cards (it's what you're paying the extra $$$ for). What good would it do for a workstation-class card to have app-specific drivers to allow the app to access the hardware directly (negating the need for OS API calls) when the very rendering technology used by those programs (OpenGL) isn't optimized too? It's also a fact that consumer-based cards are specifically optimized for DirectX since nearly all modern games are written and optimized to utilize DirectX calls. Sure some can do OpenGL too, but they typically aren't written to take advantge of all of the OpenGL optimizations/features available - and even if they were they would do so through non-optimized OpenGL drivers included with the consumer-based card. Lose-Lose.
Not really seeing the argument for a 2GB machine here apart from "I spent less money on RAM". If you're doing more than just casual gaming, 4GB or more are a necessity these days, especially when going for games built with the PC in mind (Witcher, Crysis, Dwarf Fortress, that sort of thing). Even if they're only x86 programs themselves, the simple thing that they don't have to share memory space with the OS (which forces paging, which makes computers slow) will make them run better.
No argument, and I
did spend less money. My point was this: everyone's situation is different. If a x86 OS fits the bill for me, great. If a x64 OS works for you, all of your software and all of your hardware around your home, then good for you. And since I don't play any of the titles you mentioned, I don't need to have a system that can. FSOpen is the most systemically taxing game I play - and even then with the OS and FSOpen running the system is using less than 500MB of RAM. So, if the PC I'm currently using (x86 OS and all) works for me, then that's what I'll use.
The x86 OS will be around for years to come. If you feel x86 is passe, then use x64. That's your choice and your opinion - and your opinion doesn't make x86 obsolete.