Watched the double finale last night and thought it was *really* good. Sad to see the show end but I think it was the right call. I had fallen down on watching it but decided to catch up on the last season when I was visiting the parents for thanksgiving and christmas...I was pleasantly surprised that Season 5 picked up and did really well. I think the fact that they knew it was the final season meant that you didn't get a ton of crappy filler to try and pull out a full american TV season.
If anybody enjoyed the show, its worth watching maybe the last 3-4 episodes (the double finale plus something to give you a little context about what has happened) because I really think it was a good example of how to end a TV series--which is not something that happens often on US TV.Warning: Spoiler! (Click to show)
The finale episodes had so many great throwbacks to the beginning of the show. Sarah repeats Bryce's stunt from the first ever episode (the from the opening action sequence that is a shot for shot homage to the french movie District B13), clips and settings are reprised.
The ending is bittersweet and just open enough. You have a pretty good idea that things will fix themselves but there are enough unanswered questions (like...chuck still has a pristine intersect in his head?). Even though Chuck appears to be getting everything patched up, it is a pretty brutal set of memories for Sarah to lose and not a perfectly happy ending. Also nice that it is not an ending that leaves it open to some half-assed attempt to continue the series in the future.