The topic question says it all.

There are already lots of threads about this, quick search on the forums brings me this:
 
http://forum.cakewalk.com/X3-Users-Whos-using-Tape-Emulator-and-how-are-you-using-it-m2906608.aspx?high=Tape+Emulator
 
http://forum.cakewalk.com/Who-uses-the-PC-Tape-Emulator-on-the-Master-Buss-m2936686.aspx?high=Tape+Emulator
 
http://forum.cakewalk.com/Found-a-Good-Application-for-the-Tape-Emulator-m2957069.aspx?high=Tape+Emulator
 
And for best practices:
http://forum.cakewalk.com/Tape-sim-best-practises-m2915749.aspx?high=Tape+Emulator
 
http://forum.cakewalk.com/Tape-Saturation-Theory-m501742.aspx?high=Tape+Emulator
 
And for how it works:
 
http://forum.cakewalk.com/Pro-Channel-Tape-Sim-Console-emulator-analyzed-Audio-geekery-alert-m2899028.aspx?high=Tape+Emulator
 
Hope this is helpful....
 

Um . . . thanks, but these threads don't really answer the question I posed. In fact, one of these threads is mine from earlier.
I am still looking for some fresh input on this topic.

Phil, I don't use the TE that much, but I've had some success using it on bass drum and guitar to beef up the sound.  I don't set the levels very high at first and adjust accordingly.  It acts somewhat like a compressor with color.

Oh I just noticed the first thread is yours which appears to be an identical question 5 years ago!
 
X3 Users: Who's using Tape Emulator - and how are you using it?
http://forum.cakewalk.com/X3-Users-Whos-using-Tape-Emulator-and-how-are-you-using-it-m2906608.aspx?high=Tape+Emulator
 
The other threads are mostly within the last few months...
Apols....
 

Where: usually either first in the signal chain to condition the signal prior to processing (e.g., with acoustic guitar prior to delay or reverb) or last (e.g., kick drum) to send the sound off to the mix bus with some crunch.
 
How: Individual tracks, never program material.
 
How much: Rarely, but when I do use it, it's because nothing else does the job. 

It reduces the signal - like a compressor - mostly at the mid-range point.
Driving the signal hotter = more reduction in the mid-range centered at about 2kHz
I am finding that - if one does use it - you should aim for peaks that pop at between -12 to -6 on the dial - and no more than that.

Hey Phil, tell me about Pyro.

Pyro?

Pyro is a CW program utility for editing audio for burning to CD with burner and encoder for MP3. It also can use VSTs.