I generally try to avoid spoilers, though I don't expect the world to necessarily comply with my wish to avoid them.
Despite this general spoiler aversion, I'm currently having a 'Downton Abbey catch-up marathon', and I managed to significantly spoiler myself about a number of particularly shocking plot developments by reading Wikipedia. Who would have thought there would be spoilers in Wikipedia?!
Curiosity killing the cat*, etc.
But yeah, on topic - completely agree with you about John Noble especially. Brilliant performance.
I am so glad they got a chance to finish telling their story after everything. I think the season 4 ending would have been a good ending, but I'm very hopeful that they'll do just as good a job (if not better) this season.
* I am referring to the proverb there, that is not one of the Downton Abbey spoilers.