I loved it and am glad that it ended on a happy note . I think they wrote what the fans wanted to happen and a real love story panning several decades .
You could see how Nessa and Smithy had both matured and they seemed to be great loving parents to "baby Neil ".
I think it was great that most of the strong supporting characters made an appearance as they were always integral to the story . As others have said the speech by Mick about Smithy's large role in their lives was really moving .
I was worried that having heard some interviews from James Corden and Ruth Jones that there would be a funeral / death . I did think that there may be an accident when they were on the bus driving to the port and there would be multiple deaths of the characters .
I am so glad this didn't happen as the series was never about dramatic tension but about the richly drawn characters and their at times mundane / day to day lives .
I wasn't sure about the relationship between Gwen and " Dave Coaches " but it was needed to bring him in for the drive to the airport . I suppose they could have brought in a new coach driver who had taken them to the wedding venue, but it wasn't about new characters but finding out what happened to the characters we knew and loved .
Loved the cameo though from Anna Maxwell Martin .
I don't think I twigged whilst watching that Sonia was Smithy's previous girlfriend ? I remember thinking that it was a very similar storyline with previous episodes and wondered why they had done that .Didn't realise it was the same character ....
Having read some more I see that the actress who played Sonia was kept secret, she stayed in a different hotel from the rest of the cast and she hadn't even told her family she was in it . All makes sense now 
. In my defence , whilst I think I have watched all previous episodes I watched them out of sync sometimes . Great excuse to re watch in the right order .