We use custom workflows for sales leads and support cases, because their individual status makes it easier to identify and monitor progress. I have applied these workflows to the folder level and they work great for the main task.
If I start to enter subtasks, they inherit the custom workflow, which in most cases is wrong. If for example in a sales lead the state for completed is "won", then a subtask like "do a presentation" is also marked as "won" once the subtask is completed.
I know that I can change the workflow for each subtask, but it would be, probably in most cases, easier to select not to inherit the custom workflow to subtasks.