I prefer to homebrew everything but will from time to time plug in a published mod. However, when I recently started up a second campaign, I went with SOW because of the ease in prepping. I can handle homebrewing one campaign at a time, but just don't have the time needed to run two homebrews simultaneously. As others have said, even my homebrews will occasionally pull from published mods due to either time constraints or lack of ideas on my part. Unfortunately, as much as I might plan things out in advance, over the course of 30 levels, things will either change or just plain not work as originally intended. Maybe one adventure or location I had planned doesn't cover as much XP as I had planned, or maybe it covers more and now I don't have as much room for the next adventure I had planned, etc. More often than not though its just simple writer's block or a desire to run a highly regarded adventure.