I purchased the Ducati tag bag, got it on ebay for £90 with a small tear that my wife sorted in a few minutes, good as new.
It fits well but without the bag on the bike the rear clips are sometimes uncomfortable as they flap down a couple of inches into the inside of your thigh, not a problem with the bag fitted. The tablet case for the top is pointless. I was hoping to use my iPad for navigation on an Alps trip in June but a) it's too close to your chest to read easily, b) the reflection off the clear plastic completely hides the tablet screen. Back to my Garmin then.
Good to keep your phone charging using the port under the tank. Great for toll roads as well for easy access to change and cash.
Not sure I'd be so happy if I'd paid £189 for it though.