Well, now that it has been a decent amount of time since the finale. These are my thoughts on the season. Be warned, spoilers ahead (well sort of...)... if you haven't been watching the show.
The episodes this season were generally pretty good, but honestly the "season" continued the trend of the last few since season five, just sort of floundering about with nothing really happening or progressing really. The sealing hell plot line was a little too obvious. I mean, even trying my best hold down the veil, there was just no way they were actually going to close hell unless it was the final season. Demons are the consistent (if not always primary) villain of the show, from episode one forward. The Abandon plot-line is a bit nonsensical and pointless... they effectively replaced Meg (snarky female demon opposing Crowley)... with more power but less personality (never a good trade-off). Abadon's motivations are all over the place too having gone to great lengths to get the key to men of letters bunker and then suddenly not giving two spits about it... eh. Metatron's story arch was just sort of weird, as was Naomi's. I'm not even sure what exactly Metatron feels he's accomplished with his spell. I mean, the Angels didn't particularly seem keen on chilling in heaven anyway... unless the show adds some ad hoc mythos about angels needing heaven, if anything Metatron has helped the angels by giving them more of an excuse to meddle with humanity (which seems to be their primary past time). Taking away Cas's grace is just a return to powerless Cas, which we've already seen... and Cas's special-ness has always been about God (or presumably God) stepping in for him and/or resurrecting him, not his angel-hood. Oh wow, I can't believe I almost forgot Sam's girlfriend and Benny... which says it all right there... very forgettable and seemingly tangent to the plot, even though they had sizeable chunks of the season directed at them.
I could go on and on, but honestly the problem I have with this season (and sort of the last few) is that the plot lacks cohesiveness and the writers (I fell so dirty saying this about Supernatural) are just sort of playing it safe and treading water. Everything they did this season had basically been done already and they really didn't shake things up or definitively move anything forward. Even the climatic "angels falling" twist (which anyone could see coming since the beginning of the season) basically felt like a repeat of the end of season 2 (demons released all over Earth // angels released all over Earth).
Don't get me wrong the episodes themselves are still enjoyable in a monster-of-the-week sort of way, but I miss the... epicness... the show used to have. I remember when the words "The Road So Far..." flashed on the screen, being thoroughly impressed with the chaotic but yet still cohesive and escalating tale being recapped to Carry On Wayward Son. But more and more, the show gets to that and its like just nonsensical, random, and pointless.
Still love the show, but those are nonetheless my thoughts after this season.