I caught up with this last night, and I enjoyed every minute. I know it was highly improbable, but it's fiction, we're not actually supposed to believe it!
I love that it was so happy ever after, that Mary and Edith seem to be building bridges, that Thomas is becoming nicer (especially now he's got the top job!), that Carson (grudgingly) admitted he would make a good butler, that Anna finally has her little Master Bates, that Mrs Crawley triumphantly stole Lord Merton from his witchy DiL and married him to boot! Oh and all the budding romances - Daisy and Andy, Mrs Patmore and Mr Mason, Baxter and Mr Molesley, Branson and the bouquet catcher (was that the school teacher who came a cropper with Lord Grantham once or twice?)
Watching Downton Abbey is like curling up in a cosy armchair with a mug of hot chocolate. Of course it's loaded with sugary sweetness. So is chocolate, but I'm sure we all enjoy that little guilty pleasure!
It is comfort viewing, not to be confused with historical documentaries.