This is a no-nonsense juice machine. It simply delivers a stable 9 volts to any pedal you might want to power.
As every single output on this power supply is isolated you don't have to worry about ground loops or similar issues, and it enables you to use a doubler cable which connects two outputs in serial which gives you a nice and sturdy 18 volts to power your more eccentric pieces of gear.
The 120 mA that every output can deliver can be used to power more than one pedal if their power usage is low enough (i.e. every analog pedal out there), but beware of possible issues with ground loops.
A nice and nifty feature which I haven't needed yet is that you can easily switch the mains voltage, a big plus if you travel with your gear. Just be certain to switch back when you get home!