Power Conditioner/Surge Protector

A power conditioner and a surge protector are two quite different animals.
 
A surge protector is designed to clamp off a major power surge if a line crosses or lightning strikes the line etc. before your connected equipment fries. A conditioner eliminates minor spikes and voltage fluctuations. A UPS  provides sustained power if your connection to the grid fails for long enough to shut down the computer without losing your work. Most UPS units include  surge protector circuits, but very few can be called power conditioners.
 
If you have power company current connected in the USA you probably do not need much conditioning, unless your lights flicker when a truck goes by on the dirt road out front. Actually the fluctuations a conditioner is meant to prevent would probably not even cause your lights to flicker. A surge protector is a wise idea anywhere, and a UPS in my area, where a tree falls on the line every time the wind blows, is a near necessity.
 
 

Power conditioning is largely snake oil, which is unfortunate.

 
FWIW, If you play in clubs... and have ever experience power sags... you'll appreciate a nice Furman unit. 
My Korg M3 went out of tune at a gig... right in the middle of a piano breakdown.  Uuuggghhh!!!  
That was the final staw that pushed me to go 100% soft-synths live.

 I do the same if there's any considerable wind or heavy rain and of course even a hint of lightning - unplug it. For me, that's just 2 power surgre protector bars that feed everything that I care about in my studio. I also unplug it all if I'm going to be away for more than a day or 2. No matter what though, I turn my surge pro bars off when not in use whatsoever.