Does the input gain knob (at the top of every track in the console view) not have any effect on instrument tracks? It does affect audio tracks but not instrument tracks for some reason.
 
I can lower the level of some instruments that have a master output level control, but not all instruments have this (e.g. Nanotron 2). In those cases I can't control the level of the signal before it hits the pro-channel, unless I set the pro-channel post-fader, but I'd rather not do that.
 
Is Cakewalk like this by design for some reason?

Instrument tracks are a hybrid of MIDI input controls and audio output controls. The knob marked "Gain" on an instrument track inspector is actually the Velocity Trim from the MIDI track. To access the audio track gain control, an instrument track must be split into its audio and MIDI tracks.

Another good reason not to use Simple Instrument tracks... 
I like mine separated. And then you can treat the VST instrument track just like any audio track. 

sock monkey
Another good reason not to use Simple Instrument tracks... 
I like mine separated. And then you can treat the VST instrument track just like any audio track. 

 
Same here. I also put them in a synth folder, which makes it very easy to show/hide MIDI and audio tracks, as well as take notes on the track (e.g., instrument preset or whatever).

scook
Instrument tracks are a hybrid of MIDI input controls and audio output controls. The knob marked "Gain" on an instrument track inspector is actually the Velocity Trim from the MIDI track. To access the audio track gain control, an instrument track must be split into its audio and MIDI tracks.

I've wondered why this is the case too - thanks for clearing this up scook.
 
It is really confusing though, as everything else on the strip is audio based.
 
IMO it would make far better sense for the gain knob to swap between audio gain and "MIDI" gain when you swap between the Audio & MIDI tabs - just like every other control does (e.g. Volume, Pan etc).

I often use Simple Instrument tracks. And when I want to make some changes to things not visible I split the track temporarily with "Split Instrument Track" (e.g. set the audio track to mono), then I put them together again with "Make Instrument Track". Like that I have a better overview (less tracks). Runs perfect, I like it!

Thanks everyone for the answers!

I have never taken to instrument tracks. They were only added as a feature because other DAWs had it and some users complained that SONAR should have them, too. After they were introduced with SONAR 8, I gave them a go and soon abandoned them as being too restrictive. They really offer only one advantage - keeping your track view tidy - but many disadvantages and limitations.
 
My solution is to keep MIDI and audio tracks in separate folders, ordering both in the same sequence so it's easy to locate a MIDI track's companion audio track and vice versa. This doesn't really add much clutter, since depending on where I'm at in the project's life cycle I'm going to be working primarily with MIDI or primarily with audio, and can simply close whichever track folder I'm not spending much time in.
 
Track templates can include folders, which is especially handy for multi-timbral instruments and complex routing. For example, I have an orchestral string track template that automatically creates four MIDI tracks in a folder, four corresponding audio tracks in another folder all named according to their respective string sections, loads Kontakt with my go-to string library, and routes all the audio tracks to a "strings" buss. All with a couple of mouse clicks.

Nor have I taken to instrument tracks. For the very same reasons as Dave. There is one good part to them, they can be separated and go back to a MIDI and audio tracks. This provision that they baked into them can save one from these kinds of things. 

I tend to favour instrument tracks, as I find it convenient not only for treating them as one track, but also I find it easier to swap out synths on the fly.
 
With the synth rack, I've got the MIDI track, the synth, and the outputs to separate audio tracks to deal with. If I change synths, I've got to re-route everything, which gets in the way of my workflow during writing.
 
I don't mind having duplicates of synths as I rarely get anywhere near to maxing out CPU or RAM.
 
Once I'm happy with an instrument track, I usually freeze it so I can treat it solely as audio.
 
I guess it all depends on your workflow...
 
If you've got a good idea for your song before you start recording (or a better memory than I have for keeping ideas in your head!), then separating them out will work fine.
 
I write and record as I go along. Getting ideas down quickly and developing them in the moment is priority for me.