EVERYTHING has limitations. The questions is does it/they matter to me?
Most systems have been using 32bit memory addressing for a long time but
more recently there's been 64bit systems. Unless you are doing some wild
mathematics/phyics calculations, most of use can see any difference.
SO why did they build such a thing? To allow a SERVER system to run more
services and give access to more users. (DO YOU NEED A SERVER?)
HD capacity has also been growing -- I remember when a 1GB HD was a real break thru.
Today it's junk as 200/300 GB drives are common. Does this matter? It depends
on how much data you need to keep available without accessing some offline archive.
Then too, large HDs are necessary really only when you can't attach another HD
of any size -- no more connection ports.
CPUs? Your choice of CPU is usually limited to compatibility to the motherboard.
If you're the type that needs to have the newest, biggest, badest toys in town,
then you go that way, but most of us pick reasonable off the shelf systems
(apologies to the moders and build your own group) and pick one based upon what we can affort
