The step-sequencer is one of the biggest reasons I use Sonar.  I'm an electronic musician and use it to program drums (I send the midi-data out to a Vermona MkIII and an Mbase11).  I can't believe how far out in front they are with this part of their software.  

I don't use:

Any of the VST synths (I prefer analog synths) with the admission that I think Rene is a genius.
Matrix
Staff view (haven't tried it).
 

Mod Bod

I wish someone would post something about Beatscape that would make my socks run up and down my legs and make me want to investigate it.  ;)

Beatscape causes loss of bladder control.

Bub, thanks for those links. Have you watched them ?
I believe 2 words come to mind." What cho talking 'bout Willis "
I remain unenlightened.

Hey, they were better than nothing. :)

How many have seen the Facebook poll about which new features of X2 are we excited about?  It seems to be leaning toward improvements and enhancements.   http://www.facebook.com/CakewalkInc 

I've got to say that it seems to me that Cakewalk beats a horse until it's dead instead of the other way around.  Once again, a bullet point feature is another amp simulator.  Don't we own more than enough of those already?  It reminds me of Beatscrape which was a rehash of Cyclone which was a copy of .... and on and on.

Back to my original post:  I finally did use the arpeggiator on a project so I guess I can cross that one of my "never use" list.  Maybe I'll eventually sell all my amps and cabinets and use VST amp simulators.  (Heck, I even have a vintage POD in the closet somewhere.)

Video View Matrix View Beatscape Surround Sound Navigation view (Defender view) Step Sequencer Dreamstation synth Session Drummer - any version TTS-1 Synth

 
All the above plus I'd like to add ALL soft synths.
I have things like EWQLSO and Dim Pro that get used maybe once or twice per year. But I'm basically all real instruments.
 
Mike
EDIT: V-Vocal, ACT, and after reading some of the other lists I agree with most.
 
So I pretty much use VST plug-ins, Console View, PRV, The Channel Strip and the Track Pane (forget the term).

No rewire fans?  omg, I am using rewire all the freaking time.. lol..  "I'd hate to see an unused feature dissapear." you never know when you will need it...  the magic that good engineering does.



Edit =  did you know...  you can chop audio in Sonar, do your crossfades, do your layers, and drag that clip accross windows to a rewire slave?  this is beyond radical..  actually, its retro radical, its so radical...

Beatscape - fun to play with, but not pertinent to my work
Matrix View - It could go bye bye and I would not miss it
Navigation View - I thought I would like it, but...
Notation - mainly an audio guy with a touch of midi here, so...
Most of the older synths never get loaded (probably some cool sounds in there)
ACT - not used but I'm glad it's there
AudioSnap - just can't seem to want to fool with this tool. I probably need to take the time to learn. I just don't use too many timing corrections. Usually if it is played badly, I redo the part. If it is minor tweaking, I slice and move clips parts.

Hidden Treasures:
Step sequencer can be a great tool for getting something down quick. There are also several shipped patterns that are pretty good.
Studio Instruments - these are not bad actually. I have a SI Drum template that uses two varying instances and it is a big and real sound. (versus real big sound :) )

Studio Instruments - these are not bad actually. I have a SI Drum template that uses two varying instances and it is a big and real sound. (versus real big sound :) )

I thought the Studio Instruments was a great idea as well.  Too bad it didn't go any further.

Video View -
No, because I don't work with Video, its possible that may change in future.
Matrix View - I can think of some uses for it later on if Cake takes some of my other requests for setting up a way to shift from one marker to a named marker using act to enable a foot switch like an fcb 1010 to move me around in a project live while the project is playing allowing me to use snapshots to control scene changes live and use sonar like forte or cantabile.
Beatscape - installed it the other day will explore in the next few weeks
Surround Sound - No use to me at the moment but that could change some day.
Navigation view (Defender view) - Don't even know what it is!! Step Sequencer - can't think of any use for it
PRV haven't explored using it yet
Dreamstation synth - Never used it probably never will with better synths included
Session Drummer - I like it now but later on I will go to Superior Drummer, soon.
TTS-1 Synth - got VI one and proteus VX to work inside reaper rewired inside sonar
Arpeggiator - have not messed with yet
Publisher - Not yet External Inserts - Not yet
ACT - Not yet but I have a pcr500 and I will eventually.
Rapture and Z3ta I love these and dim pro even has some good sounds I love all the synth stuff but there are lots of free synths that are very good to use if you research KVR.
REX files (RPX)not yet
Audio Snap not yet
V-Vocal not yet
SFZ and SFZ+. Dimension pro is something I am just starting figure out very cool
V-Vocal pitch-to-MIDI plan on exploring this very soon

I'm a guitarist who plays keyboards some and I plan on adding superior drummer and getting a Roland GR55 next. I want to import drum midi files and integrate SD2 as well as use the GR55 to play virtual synths from my guitar. I mostly am learning to use everything now and reading a Garigus book I purchased