I took a look at what this plugin does through a frequency analyzer and it's truly amazing what it does. Unlike most analog emulations which
add harmonics, this one actually
removes existing harmonics and
replaces them with genuine analog ones. Take a look:
BEFORE
AFTER
This is a low E played on a Squier Precision bass. As you can see, the Rack Spacer plugin has not only replaced the horrible artificial harmonics of the original with analog ones, but it has also
increased the perceived value of the bass to something more like a Fender Precision. Dave Pensado is going to go nuts with this on his video tutorials.