Anyone had problems with 64 bit OS?

After reading Wikipedia article on 64-bit processing, I found some disadvantages of a 64 bit OS compared to 32 bit OS’s.
[]Data takes up a little more RAM due to swollen pointers and possibly other types and alignment padding.
]64 bit versions of device drivers must be available. You cannot run 32 bit drivers in emulation mode on a 64 bit OS.
[*]Some early 64 bit Intel processors had poor 32 bit emulation.
So has anyone had the above problems or are these facts antiquated? With current technology, have all these problems been fixed? I’m considering moving up to 64 bit processing.