I downloaded Everett this morning, and briefly tried the new "Sizzle Bus" preset. Subtle and surprisingly useful. I tried it on a snare sample, and on a Martin acoustic guitar track that was recorded with an AEA R84 ribbon mic.  In both cases it added some air  around the source, and added a nice high end without being brittle.
 
Nice job on this one Craig!

Glad you like it! I also find it very useful, particularly on tracks recorded with dynamic mics. On some older material, I even use it as an overall processor on the master bus. You have to be careful not to overdo it, but I feel the results are much better than just boosting treble to add "air."

I realise the innards of these things are hidden for a reason, but can you give us a rough explanation of what it's actually doing?

It's actually fairly simple. From the Sizzle Bus section in the Everett issue of the monthly eZine:
 
HOW IT WORKS
The Sizzle Bus uses a high-pass filter to eliminate all but the highest frequencies, which are then distorted to create artificial harmonics above the natural harmonics. This is similar to how the original “exciter” hardware circuits worked. Keep the bus fader low; you don’t need much sizzle to create the desired effect.
 
THE CONTROLS
HF Cutoff sets the high frequency cutoff from about 8.6 kHz to 17 kHz.
Sizzle adjusts the aggressiveness of the distortion.
Delay delays the sizzle signal from 0 to 2 ms. Longer delays can give more depth.
Width varies the stereo placement from mono (control counter-clockwise) to stereo (clockwise).



 

For those who have Reaktor, there is a user library entry that does something similar:
 
http://www.native-instruments.com/en/community/reaktor-user-library/entry/show/6109/
 
From the entry description:
 
"It extracts treble frequencies, compresses them, runs them through an asymmetrical soft saturator, and then mixes them back into the original signal."
 
The curious can open it up and change things a bit.

Anderton
Glad you like it! I also find it very useful, particularly on tracks recorded with dynamic mics. On some older material, I even use it as an overall processor on the master bus. You have to be careful not to overdo it, but I feel the results are much better than just boosting treble to add "air."

My findings exactly.

It's very nice; thanks a lot!

Thanks Craig.
 
I also have Reaktor and have compared their effect to Sizzle.  Both do a quite nice job with very little input.  I would compare both with BBE's Sonic Maximizer, either the VST plug or the hardware model 802.
 
I have used BBE's component for years to brighten up cassettes and LP's when making master cassettes for duplication. 
 
Now I can just have Sonar running, instead of Reaktor when I think it is a overkill.

I will have to give the Sizzle bus a try tomorrow. Sounds cool

Please check out the documentation in the Everett eZine, that's the only existing documentation for it.