@BRuys: Yesyes, I got it, I got it.
Its the button with the waveform on it. And the markers in the menu.
Been there since Sonar 8. I just use them when I need them.
I never knew their technical name nor that they're unique.

1. Do you use the waveform preview feature?
C. I use this feature often
 
2. Do you use this on buses or instrument tracks?
A. Bus waveform preview
B. Instrument track waveform preview
 
3. Waveform preview allows you to display historical peak markers on the timeline. Do you use this feature?
C. I use this feature often
 
4. When do you use this feature in your production?
To see the cumulative effect of effects and bus sums. To look for peaks that may need to be reduced. For setting up precise bus automation. Probably more I can't think of at the moment.
 
While we're on the subject... I wish there was a feature in Sonar that would quickly run through waveform preview and track waveforms, at possibly selectable different points within the processing (before, after, between?), at high speed, and would flag a selectable number of peak points (like 5, 10, 20, etc.), in descending order, to use for quickly and precisely spotting peak problems so they can be taken care of in differing ways, depending on how many peaks are found and their characteristics. If there's just 1 or two, I might want to deal with them by manually setting up automation. A few more, I might want to use a little more compression, or a limiter or clipper, depending on characteristics of the track. And if a large number of peaks are found, I might want to go back through the signal chain and find the specific source of the problem, or where I might want to deal with the problem and its cause. All without having to play thru the track multiple times to find them.

 
Not surprisingly in just 24 hours this just happens to be the 11th most popular post ever in these forums.
 

Noel Borthwick

1. Do you use the waveform preview feature?
A. Wasn't aware of this feature
B. Aware of it but never use it
C. I use this feature often
D. I use it occasionally

C. I always use this at least on the master bus.
 
2. Do you use this on buses or instrument tracks?
A. Bus waveform preview
B. Instrument track waveform preview

Mostly buses, so A.
 
3. Waveform preview allows you to display historical peak markers on the timeline. Do you use this feature?
A. Wasn't aware of this feature
B. Aware of it but never use it
C. I use this feature often
D. I use it occasionally

I used to need this a lot and used it then to detect peaks, but these days, between bus gain nobs and concrete limiter, I don't go red.

I do need the ability to detect heat in the pro channel. Clip hold at the very least. Fast bounce clip detect preferred. Take me to clips after detecting.
 
4. When do you use this feature in your production?
When needed.
 

Once on, I only turn it off when it is in the way of reading envelopes.

Noel Borthwick [Cakewalk
 
1. Do you use the waveform preview feature
C. I use this feature often
 
2. Do you use this on buses or instrument tracks?
A. Bus waveform preview
B. Instrument track waveform preview
 
3. Waveform preview allows you to display historical peak markers on the timeline. Do you use this feature
C. I use this feature often
 
4. When do you use this feature in your production?

I use it for a few things... I look to check dynamics and determine limiter/compressor needs/uses as well as overall volume of these teacks and busses during mix...

Thanks! This is a very handy feature!

Keni

1. Do you use the waveform preview feature?

D. I use it occasionally
 
2. Do you use this on buses or instrument tracks?

B. Instrument track waveform preview
 
3. Waveform preview allows you to display historical peak markers on the timeline. Do you use this feature?

C. I use this feature often

 
4. When do you use this feature in your production
 
mostly in final mixing to see if I go over.

Adq
...It is too inaccurate and every time it is drawn a bit different...So usually I use it just for rough information about sound.

 
I once tried to use the waveform preview to check a timing issue but it was nowhere near accurate enough to use for that purpose. It's still very useful though. But you are right, it would be even more useful if it were more accurate.

1. Do you use the waveform preview feature?
A. Wasn't aware of this feature
B. Aware of it but never use it
C. I use this feature often
D. I use it occasionally
 
2. Do you use this on buses or instrument tracks?
A. Bus waveform preview
B. (Rarely) Instrument track waveform preview
 
3. Waveform preview allows you to display historical peak markers on the timeline. Do you use this feature?
A. Wasn't aware of this feature
B. Aware of it but never use it
C. I use this feature often, and would go into a corner and pout if it went away
D. I use it occasionally
 
4. When do you use this feature in your production?
 
When mastering within SONAR and you want to at least win a skirmish in the loudness wars and match average levels among files, this is invaluable. Seeing the waveform visuals, and setting the master bus meter to a +12 dB range, make it possible to match levels visually to cuts recorded previously. Most of the time you'll be in the ballpark without having to spent a lot of time A-Bing.

Craig, I'm interested that you judge loudness by ear rather than measure it over time with an EBU meter (this is what I do). 
 
As I mix, I keep an EBU meter on the master bus and I increase and reduce compression to keep limiting to a minimum, ensuring at least a touch of limiting occurs. It helps me set compression in context of available headroom.

1. B
2. None of the above
3. A
4. I don't/haven't