I've done a few hands off ones (none of them AARs) and I normally quit them when something happens that I didn't want to happen:
CK2s BBB (Big Byzantium Blob), Holy Roman Empire manages to incorporate Hungary, Poland etc, Golden Horde loses their war too Bulgar or Cuman (I'm a huge fan of the Mongols, for their promotion of religious tolerance, free trade, decentralization and state rights), France takes full control of Spain, etc.
I actually enjoy hands off games and seeing how they turn out. My longest hands off game saw me quit in 1267 (just over 200 years into the game)
I played 2 hands off games in Vicky 2 from start of the game to the end of the game, Starting as some Cambodia and switching over to Luxembourg or Krakow as soon as I become westernized (which was in the 1910s or 1920s so I didn't exactly play as Europeans for long.
My current hands off one I am really tempted to quit because 2 things that I didn't want to happen happened, but the cluster **** in England has just been too exciting. It was only 20 years ago that in game that I noticed how large France was cause I was just zoomed in on England watching the warring states.
England have 27 different kings from 7 different dynasties since the start of the game has been too exciting not to watch. 200 years of civil war and no end in sight.