In my opinion, loops are far more useful in the RB environment, because you can have many more instances and you can put them exactly where you want them.

the RealBand video is now available.. although I haven't had time to watch it yet, I suspect it has some info about how to use loops.

Also, if you want an overview of how other software uses loops, you can go to youtube and search for phrases like "Loop based music" and you'll get plenty of hits.

It wouldn't surprise me to see some enterprising forum buddy make a video on using loops with RB and post it to the user video section.