The date on that review is from nearly 2 1/3 years ago. Many improvements have been made since then - with remarkable improvements made in the area of graphics performance due to nVidia and ATI witting better drivers.
No one lost openGL support as every one who uses openGL for anything remotely productive uses the vendor drivers which support OGL better in the first place.
As for using the hardware less effectively - that isn’t correct. With 4/8GB of RAM techs like superfetch make the system much more responsive as do the kernel and scheduler enhancements for multicore processors.
*Is there a warning somewhere that tells us that we will need to replace perfectly functional hardware?*
That is a flat out and out misstatement of reality - Microsoft publishes a HQL and if the vendors don’t update their drivers take it up with them.
To quote an article "Windows Vista is a bloated pig of an operating system. In fact, compared to Windows XP with Service Pack 2 or 3, Vista requires roughly twice the hardware resources to deliver comparable performance."
You apparently like Vista, I don't. I belive the marketplace tends to agree with me, as Vista was bluntly refused by the marketplace. IMHO, MSFT is in a very tenuous place. They came out with WinME, which was a colossal mess. Shortly thereafter, MSFT came out with WinXP. People who dropped money to upgrade from Win2K and bought that POS, WinME, felt that they had been cheated. And rightly so, WinME should never have seen the light of day. Much the same can (and has been) said for Vista. Win7 apparetnly is, what Vista was supposed to be. This goes right back to 'Quality'.
Where WinXP would allow applications to run in 'emulation mode', Vista does not. What do we gain, by dropping something that allowed legacy hardware and software run on our machiens? Basically, we traded legitimate needs for some fluff (Aero) while we lost something commonly used in most offices, Instant Messenger. (You do know that Instant Messanger is missing essential APIs so it crashes under Vista, without regard to SP releases, don't you?)
Superprefetch is really a misnomer. The South Bridge chip usually maintains a pre-fetch register that is capable of holding 2-8 quadwords. This 'should' be handled in hardware, not software. The entire point of 'pre-fetch' is to prevent unnecessary latency while the hardware negotiates to talk to memory, or HDD. Still, WinXP has pre-fetching turned on - and I have yet to see a benchmark comparing WinXP to Vista's pre-fetch routine.
The last point is that your 4/8 Gig statement. Go ahead and load 8 Gig in your 32 bit machine if that makes you feel good. The fact is that depending upon your BIOS, you will only see about 3-3.5 Gig. 32 Bits only allows you access to 4 Gig. For the 64 bit machines, you can go a bit larger, but what percentage of users have more than 2 Gig in their PC?