At least the show has ended on a high. If the producers have any sense they'll end it at the end of this season. To make another would be a season of "jumping the shark" of character behaviour on a most basic level.
The trust between Castle and Beckett has been totally destroyed by the way they did this. It could have been done so many other ways without destroying the trust and allowed it to go on. That conversation will be relived over and over for the rest of the character's lives continuously eroding any trust and confidence one has in the other. Castle may be a consultant of sorts on this show; however he choses to go into life-threatening situations with Beckett. You have to be able to trust your partner when that happens. With the way they've done it, over a short period of time he'll find he can't trust her even that much as this will eat away.
The storyline was reasonable albeit superficially dealing with the subject matter. The twists and turns were nicely done and not too many eye-rollers for forensics or computer functionality.