So it ended ok, Gideon wasn't quite the all powerful unbeatable evil he was built up to be for 3 seasons, and the end of the world was confined to the side room floor boards in Locke house, so it could have been bigger I guess, but the exit plan was sound, and it did wind it up nicely and finish it.
I'd much rather it went on for a couple more series if the source material was good enough, more experimenting with keys and the repercussions of that, but if it mean we had to suffer through episodes like duncan's wedding again, or mum's issues with alcohol, maybe it's for the best we leave it here.
I personally think there was a lot more to be investigated. More keys, we never understood the other world at all, it's just where bad people come from and go back to. I don't know if I trust our writing team to manage that well though, there were a few too many clunky story elements and mcguffins that insulted our intelligence, but then again, there were a lot of good moments, and some of the characters were excellent.
Thanks for an entertaining 3 series. I'm sad to see you leave, appreciate what you delivered and would have liked to have seen it go somewhere further.