5400RPM on games

I don't think it will make much of a difference. It might take slightly longer between load levels, but once the level is loaded there should be no difference.

So you wanna tell me that people spend the same amount of money on SSD and HDD while the HDD has larger space? all of that because of loading times?

If this was directed at me, the OP is discussing 7200rpm drives vs 5400 rpm drives, not an HDD vs 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).