I inserted the PC tape emulator before Ozone while mastering a tune today and I liked the results. Very subtle but helped make the sound less brittle and somewhat glued the instruments together. Anyone else doing the same of are you just using it on individual tracks or submixes?

I'd say "if you like the result then do it"
 
I personally don't because I restrict myself from doing anything on the master bus. I believe in leaving that task to a separate engineer. 
 
Hence, I used tape emu (PC tape emu, WAVES J37) mostly on individual tracks or on mix stems (which is as if you'd be bouncing your mix stems to a tape machine)
 
 

Whatever works for you.
 
I like the tape emu on tracks.  Nice low end bump.  But I don't like the console emu - I think it puts a skrim over the sound.  Go figure.  So, whatever you like.
 
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I sometimes put one on the master bus. With light noise. Not much.

I use it on all buses including the master. I rarely use it on individual tracks.

Thanks for all your responses! I'm also of the "if it sounds good, do it" school of thought! I always close my eyes, listen carefully and try not to get fooled by volume changes. And by the way, I misspoke when I said I put it on the master buss. I use it during the mastering process.

I actually forgot i have the PC tape sim. How is it?? I have not used PC since X1b. If  it as good as the KMT, i,m  on board .

I set it up like it's an old analog chain with Console Emu first and then Tape Emu. I put the CE on all tracks and busses and the TE on tracks and master bus. I love the sound of the two together. Very smooth and warm.

FreeFlyBertl
I personally don't because I restrict myself from doing anything on the master bus. I believe in leaving that task to a separate engineer. 

Yes yes yes yes yes!!!!!!!!!