So by accident, I bought a new computer with a 5400RPM 2TB Samsung HDD.
Now my biggest concern is not about the transfer speed and load speed... not at all...
I'm concerned about games, really concerned since Diablo III is coming out.
Does it really matter (on games only) if it's 5400RPM or 7200RPM? Would I feel any difference? Even if it's 0.01% change.
(Be gentle I really don't have the money to buy now a new 7200RPM HDD or moreover a SSD)
A 5400RPM HDD is not that bad. They are certainly faster than 5400RPM HDDs from several years ago because the data is densely packed. However, they are still considered "slow" by today's standards. Generally speaking, it means the 5400RPM will probably take a couple of seconds (or a few) longer to load a game.
Some people simply want Windows 7 or any app/game to load as fast as possible. If you want to sacrifice storage space for speed, then buying a SSD is the way to go. Personally, I don't mind waiting 50 - 60 seconds get to the log on screen. But some people want to get there in 20 seconds (or less).