The software is quite ok, but, there are a few "buts":

4K does not take note of all new entries in the subsciption list - its behaviour is very erratic.
It would be nice, if 4k would not jump into action as soon it is envoked. A moment to check the directories it would write to, would be highly appreciated - than a button named "Run" should be available.
If the subscriptiion list shows new files to have arrived, 4k does nothing! It would be nice if one could MAKE 4K retreive actively thoses new files. Maybe a button named " Refresh your subscriptions and download" would be very helpful.
Hope to see one or two of my suggestions come in to live, apart from this it is already a great software.
(only on occasion it fails to download or merge, Luckily Video Downloader Ultimate can fill in here and download those files, 4K fails)