dcmg
After pitchy singers, acoustic guitarists with dicey timing is my most laborious and frequent editing scenario. I intend to keep plugging away at Audio Snap in the hopes that it becomes a time-saving tool in that scenario. As always, the real-world tips and shortcuts are mucho helpful :)
I believe you said you bought "The Big Book of SONAR Tips." In the AudioSnap chapter, check out the tip on page 243, which relates specifically to fixing dicey rhythm guitar parts.
An important point about AudioSnap is it's not enough just to have markers at every transient. You also need to disable markers that occur within a single continuous block of sound, like a chord, so you don't stretch half a chord but not the other half.
Try the tip a few times, and AS will become second-nature for fixing guitar parts.