Never had any luck with batch quantizing, I do it with audio transients. Change track clips to transient, zoom in, if you click on the track you can bring up the audio snap window - I like to slide the threshold on the right to about 75% that cuts down on the number of markers generated. Then you can shrink or stretch you notes as needed. This takes some trial and error and it can be over done where it distorts the sounds. I frequently move the markers to more precisely manipulate the segment. I always align the bass with the drums, it's amazing how much tighter the track sounds after that. Rhythm guitar, you have to be conservative because it can make for weird sounds. Pretty time consuming but I find it fun.