What is the definitive tutorial on audiosnap?

The most helpful one for me is the section in the SWA X2 vid series by Karl Rose (but if you are going to buy it get the "Complete" package which has all the new stuff from X3 as well). It is quite through.
 
The other one that is helful and is more real world application is the CakeTV Webinar from a couple years back Drum Production. They work extensively with Audiosnap for multi mic drum correction so you get a good feel of what's going on.
 
Also I recommend going through the Transients edit filter/Audiosnap sections of the manual (there may be mutliple entries) to really nail down the little this and thats of the process. Create a little cheat sheet to keep by the computer because it's hard to remember everything (it's quite a complicated tool).
 
A couple things to be careful of based on my past experience with it...
 
Crank your buffers as high as you can stand to help minimize glitchiness.
 
Disable your AV. I don't care what anyone says, even MSE screws  around with audio work on my system. However you may be able to get away with just whitelisting all the Sonar stuff BUT it'll still be screwing around in the background so I just turn it off unless I'm online.
 
Maybe see if there are any updates for your graphics card because a lot of my issues were with grphical glitches that snowballed into actual problems (and sometimes crashes).
 
Do NOT close Sonar before finishing your transient work, bouncing and then saving the project. I Saved in the middle of a long AS session once and it completely corrupted the project. It was awful. I would also recommend doing a specific Save As of the project to work on Audiosnap stuff in case something liek that happens.
 
I don't mean to sound terrifying with all that because all my AS issues were in X2 and I haven't really screwed with it much in X3 yet (nor do I have Platinum). By all reports AS is much more stable than back then but it's better safe than sorry.
 
Cheers.