When I buy plugs for use with Sonar I try and find out what the latency will be. I have no idea what kind of latency Sonar's plugs have and I'm wondering if anyone else knows. I love the way Waves posts those specs, so maybe this will be a feature request.
 
Do Pro Channel modules have zero latency?

I do not recall ever seeing a comprehensive list of Cakewalk plug-ins with this type of detail. Waves may post the information to assist when PDC must be calculated by hand.
 
WRT the ProChannel, the Concrete Limiter carries a notation about latency near the bottom of the "Using the Limiter" help page:

Note: ProChannel Concrete Limiter should not be used on a track while recording, as it has a look-ahead of 1.5 milliseconds and will result in a slight delay while recording.

I believe it is the only module I have with such a notice.

There are occasional posts about Cakewalk-included plugins and which ones add enough latency to be unable to be effectively used during tracking, but I have never seen a complete list in any of those.
 
I guess I would look at descriptions of each suspect plugin in the Sonar documentation, and  then I also have a general sense that plugins that are in the Convoluted Reverb category likely add too much latency for use in tracking, just by the nature of what they do in their processing for the effect.
 
Many 3rd-party plugins post latency values on their websites, and that really helps.  I am shortly going to embark on several large-scale projects, and one of my by-products from that will be that I will start and retain a Word document that lists each of my plugins by category, vendor, name, description, and notes, with some sort of marking/note to indicate which ones are not to be used during tracking.  If and when I get enough of that finished, I will likely publish it here in the forums, for others to copy/paste into their own lists.
 
Bob Bone
 

Record with FX off to be safe and also avoid potential timeouts and / or crashes.    When I do overdubs, I create various mix or stem tracks in advance with FX and mute all the other tracks.   That way I can enjoy mixed base (not bass) tracks for overdubbing but keep the FX off and live track playback to a minimum.    

In your quest for identifying latencies, be aware that many plugins have variable latency, a category that includes those most notorious for long latencies. Remember that what causes latency in a plugin is buffering. If a plugin offers a buffer size option then there is no single number that represents that plugin's latency. If an equalizer offers a choice between minimum phase and linear phase operation, then it, too, has no single latency number. Plugins with multiple modules (e.g. Ozone) will have variable latency depending on which modules are enabled. 
 
Latencies can be measured, IIRC, by Christian Budde's VST Analyzer. If you're not familiar with that tool, google it - it's a free download. Unfortunately, VST Analyzer could not load 64-bit plugins last time I checked. However, if you have the 32-bit version of a plugin available, even if it's not registered in SONAR, you can test that instead and whatever latency you measure for it will be the same as for the 64-bit version.

Don't forget about plugins with 'look ahead'.

I was aware that all plugs have some sort of overhead. What fascinates me is that Waves lists the latency by platform and recording frequency plus some plugs have less latency when recording at 96k than 44k or 48k. That's got me wondering if ALL plugs have less latency at 96k. So far it's not consistent.
 
I'm shopping for a Quad Curve replacement and want something very similar. THe Waves H-EQ is very similar to the Quad Curve but has some latency at 48K recording. I only use multi-band plugs and limiters for mixing. Same for reverb.

stxx
Record with FX off to be safe and also avoid potential timeouts and / or crashes.    When I do overdubs, I create various mix or stem tracks in advance with FX and mute all the other tracks.   That way I can enjoy mixed base (not bass) tracks for overdubbing but keep the FX off and live track playback to a minimum.    

But my singer/guitar player needs to hear his "tone" when recording...

Right ... it's also sometimes a factor in making a mix, without the FX, whatever it is, the sound isn't right, and it is extremely difficult to imagine a future improvement while working without it. 

Hey William, to deal with that issue I just bought a new interface that has onboard DSP that matched bundled plug ins. No latency at all while recording and I have a selection of reverbs, a comp and EQ to use. The reverb is one of my favourites and I find singers really like to have a bit when tracking.