The main culprit for noise in pedal chains is the ground loop. The biggest cause of this is the wall wart transformer. Also, the makers of the wall warts tend to skimp on filtering. Both of these make for a noisy supply.
The 1-spot eliminates this because of the serial connection. However, it can be a problem for mixes of pedals that have different requirements.
The Voodoo Labs Pedal Power2, on the other hand, is really the best way to go all around. With each output isolated, the problem of any ground loop is eliminated. It also has different configurations for pedals that have different voltage requirements.
I would rather be a jack-of-all-trades and master of none, than be a one trick-pony out of a job.