I'm perfectly fine with someone keeping an old PC and continuing to run XP, but have to chuckle at the people who think that it's faster than a new OS on new hardware because it uses fewer resources. The thing is, your hardware isn't truly fully supported even if the vendor provides the latest drivers. XP was designed for Pentium era hardware. For example: it does not take advantage of improvements in CPU architecture. Heck, it doesn't even take advantage of the copious amounts of RAM we have these days since it had to use more conservative algorithms for older hardware. Even things like the GPU isn't fully used by the Windows itself, even though applications have access to it.

Old OS, old hardware: fine. Old OS, new hardware: it's your choice, but don't expect it to be any better.