Brilliant! Apart from precision in a custom slicing (in LCV), there is one more advantage of having the process inside Sonar, which is speed (some vst samplers need time just to open, to initialize a new empty instrument, drag'n'drop is not guaranteed so you need to open a browser to navigate to the loop).
Two minor questions:
1. With the whole loop selected, I hit tab and S, then the selection goes to the left side of the cursor, so I need to select the right side of the cursor (containing the part of the loop that has yet to be sliced) before hitting tab and S again. Your video was amazingly fast because the right side keeps always the selection. Where do you set the option, on splitting, to keep the right part selected?
2. drag'n'drop of individual slices to Session Drummer 3 and Rapture Pro worked fine. When I drag to Matrix View the cell plays the whole loop. Which option should be set there? From your video you don't seem to trim the individual clips nor bounce to clip.