The ending left me quite disappointed. I was really getting emotionally into the characters reconnecting/reuniting with each other in the flash-sideways plot, but once the ultimate direction of that plot became clear, it wrecked it all.
The whole "Purgatory Lite" thing was ridiculous. "You all created this place to meet each other again before you moved on." Say what now? It was just another "St. Elsewhere"/"It was all a dream"-style ending. It's been done to death, Hollywood. Let it go already.
Plus it completely throws off making any sense of the show. First off, in this "Purgatory Lite," there were people getting hurt, people dying (when they were already dead), people being pregnant and giving birth, etc.
And if they created this afterlife to meet each other again, what's with bringing in people like Martin Keamy? Did they really want to reunite with him?