Enhancement without Loss of Quality
There are tons (probably too many) tape emulation plugins out there, and I've used most of them. Many people are "wowed" by most tape emulation plugins immediately because when they insert it on their tracks it sounds bigger and fuller. However, 95% of tape emulation plugins actually just distort the signal slightly (reducing the quality of the audio) and then boost the signal by 0.5dB or so. The increased volume leads you to believe that it's better and fuller, but in reality the opposite has happened.
The Crane Song Phoenix is NOT one of these plugins. After doing many blind tests, this plugin has proven to make almost any track sound better at equal - or even slightly less - amplitudes. After doing some analysis, it appears that this plugin actively reads the fundamental frequency of the signal and adds musical harmonics to it. This is a known effect of analog tape saturation, yet most "tape emulation" plugins just distort the signal (adding non-musical saturation, i.e., harmonics that aren't related the fundamental frequency).
Because of this, I cannot give enough praise to this plugin. The effect is subtle, so I recommend adding it to each and every track in your sessions. This will give you the most accurate tape emulation, as the effect of the tape saturation really starts to work its magic when all of the tracks are summed together (obviously all those famous songs recorded on tape had many many tracks summed together).
The only reason I'm giving this plugin a 4/5 instead of a 5/5 is because it is NOT REQUIRED to make great music! So many people get obsessed with the equipment and plugins, they forget that what really matters is the engineering technique and the musician. However, if you have the expendable cash, and you want a true tape emulation, this plugin is absolutely stellar for its purpose. I cannot recommend any other tape emulation plugin as high as this one (although respected people will rave about the Slate VTM, many tests have shown that it does in fact degrade the audio quality, as talked about above).
In case you aren't familiar with Crane Song or the man behind it, David Hill, you should know that he's a true genius in audio technology. He single-handedly popularised the PWM compressor, and some piece of his equipment is in almost every high-end mixing or mastering studio.