I need to determine the best replacement/augmentation method for my situation. I have an excellent drum performance with a thin sounding snare, (i.e., it’s the drum itself, not the drummer). I mic’d the snare, so it’s recorded with virtually no bleed.
 
In a 2007 thread, Scott Garragus wrote that drum replacement could be accomplished without any extra software.
 
“You can use Audio Snap to extract the groove from the audio and convert it to MIDI. Then you can use this to trigger a soft synth (such as Session Drummer 2) to replace the existing drum sound.

I have an example on how to do this in my Sonar 6 Power book... check out page 248.”
 
I own a copy of his book, but it’s in a different state, and I won’t be able to look at it for at least a few days.
 
Here’s the problem: The song was recorded with a click track, but all the hits aren’t perfect, even though they’re pretty close. I actually PREFER this – the drums to not have “perfect” timing. Does Scott’s method require a recording to be perfectly lined up BPM wise, or does it impose replacement sounds that are perfect and have to be manually aligned with my snare recording? Or, does sense the hit and put on a replacement sound at exactly the right moment?
 
Are drumagog or Aptrigga any easier for such an application? I’ve read good things about both. The important thing is that I want the replacement sounds to have the exact timing of the original recording. I assume this will take some manual editing, but is there one method that senses the hit and puts on a replacement sound at exactly the right moment better than others?

I have done this with Kick drum and it works perfectly. Only difference is you'll select D3 as your MIDI Note. You can change this latter anyhow. 
 
The trick is a nice loud transient track and with little or not bleed. 
All the information you need is in your help files so you don't need the book. 
I just followed the directions and it worked first time. 
 
As far as quantization goes, no you don't have to apply it. Audio snap extracts the data, it does not have to quantize unless you tell it to. It is the best use for audio snap , drum replacement. 
 

S6's implementation of Audiosnap is different from the current release, but the process goes something like this;
 
- Right-click the clip and enable Audiosnap
- Right-click again and open the AS Palette if it isn't already up.
- Choose the Extract Groove radio button
- Click Copy as MIDI
- Now the hits are in the clipboard as MIDI events, and can be pasted wherever you like.
 
Before copying, you can set what MIDI note number is generated under Options in the AS Palette. I don't recall if Audiosnap 1.0 generated velocities proportional to amplitude, but that option will also be there if it does.
 
If you find you have extra/missing/mislocated events, you may need to go back to the clip and adjust which transient markers as active, and where they're located. Or you can just edit the MIDI, depending on how many errors there are.