This would be ideal for me if the sleep function would just stop playback in iTunes, instead of making my entire computer sleep, as I usually leave tasks running overnight, which I obviously don't want interrupted.
I see that you can create "alarms" that stop playback, which might do what I want, but that means I have to calculate when the "alarm" should trigger based on the current time and the amount of time I want it to play, and basically defeats the purpose of having a sleep timer. I just want to set it to turn off the music in 90 minutes. There's no way to do that without also making your computer sleep, and waking up to find all the tasks you left running didn't get done.
The interface is cluttered, confusing and unpolished. The UI for creating and editing alarms, for example, is pretty awful; there must always be at least one alarm in the list, but you can't edit any of the properties of an alarm after it's been created, except its name. So you must first create a new one (and get all the settings right, cause you won't be able to change any of them), and only then can you remove the default one from the list.
Sure, you can't argue with free, but considering it doesn't really do what I want it to do (and makes it frustrating and difficult even to use it for its intended purpose), I'll have to find something else that does, even if I have to pay for it.