What are the advantages of having tight voltage regulation?

[Miraluka]

What are the advantages of having tight voltage regulation?

 

[Jhhnn]

Three things:
1. stability
2. stability
3. You guessed it, stability.

When the machine is running, the current draw can change suddenly, starting the cdrom or a drive, changing the cpu load, etc. When this happens, the less change in voltage, the better. Cheapo psu's don't do this very well, and can also vary in voltage with temperature. As with anything, I'm sure there is a point of diminished returns depending on your system and how you use it.