I wasn't a fan of what they did with this episode at all, very anti climactic. I mean all of that elseworlds nonsense to come to the realization that Castle and Beckett are better together than if they'd never met? REALLY? We didn't need that to get to the wedding that was shoehorned in at the end.
The actual scene itself was nicely acted by Fillion and Stana but that backdrop looked so fake and why were Espo, Ryan and Lanie not there?
Overall it felt like they reacted to the negative feedback to last seasons finale and just decided to get the wedding over and done with after all the build leading to a bait and switch last time.