I am recording from softsynths and hardware synths (not sure that matters), but my kicks and bass I like to be true mono.

Setting Interleave=Mono is not really mono because it is a stereo track interleaved into mono.
 
I remember back in Sonar 8 you can choose either a stereo or mono track.  If you chose mono, you would only see 1 centered waveform in track view, not 2 for L/R.

Thank You,
Adam

In the track properties panel of an audio track, open the dropdown list under inputs and select ONE of the channels of your sound card (stereo is selected by default). You have a mono track and the display updates to a single wav image accordingly.
 
Alternately, if you have a stereo audio track, you can bounce it to a mono track.

czyky
In the track properties panel of an audio track, open the dropdown list under inputs and select ONE of the channels of your sound card (stereo is selected by default). You have a mono track and the display updates to a single wav image accordingly.
 
Alternately, if you have a stereo audio track, you can bounce it to a mono track.

Interesting, but what if you have a stereo track with different information in L/R, but just want to mono-ize the track.

Is setting it up for "Interleave=Mono" acceptable or does that do something strange to it?
 
I am unsure what Interleave is actually doing.

Thank You!

Interleaving a stereo track to mono simply mixes L and R together and outputs them as mono. Similarly, setting the interleave on the master bus to mono results in a mono mix. This is the easiest way to check how a mix will sound on mono playback equipment such as a club sound system, mono radio or TV etc.

If you create a track and select a single interface input (usually indicated by Sonar's less than user-friendly naming scheme as "input 1 L" and "input 1 R" etc) as the track's input then the track will be mono by default.

Understood, thank you.
If I have a patch with some stereo information though, is it acceptable or OK to just use the Interleave=Mono option?  this way I am capturing the differences between the L and R channels or does this do something unwanted to the audio?

Understood, thank you.
If I have a patch with some stereo information though, is it acceptable or OK to just use the Interleave=Mono option?  this way I am capturing the differences between the L and R channels or does this do something unwanted to the audio?

No I don't think it does anything 'unwanted' to the audio.
 
As an aside:
You can also bounce the track to 'Split Mono' - creating 2 bounced mono tracks (L and R).
Tracks > Bounce to Track(s)
Source Category: Tracks
Channel Format: Split Mono
 

Or use the Channel Tools plug-in to select the channel to use dynamically.

KPerry
Or use the Channel Tools plug-in to select the channel to use dynamically.

would that be preferred over the interleave option?

I use Channel Tools on all of my synth tracks to place them precisely where I want in the stereo field.
 
And yes, this includes those rare times when I use a kick not from BFD (which is mono) or any sort of Bass patch.