That's it. I have my files structured by albums. Also, the 450 and 550 have a limit of 1000 songs. I've stitched the songs together in some albums using Direct MP3 Joiner so they appear as a single MP3 file. I have well over 1000 songs in 72 subfolders and they take less than a minute to load. The Zumo thinks I have about 600 songs. It does take a couple of hours to play the compilation title in a Beatles album though.
Pat- 2007 DL650A was ridden to all 48 contiguous states. 2012 DL650A is just getting started.
Nicknames for posting ease on my part, Vee = all DL1000s. Wee = 2004-2011 DL650s. Glee = 2012+ DL650s