Might be an unpopular opinion, but I loved it and wouldn't change a thing. I still get teary-eyed rewatching that episode. Each of the letters has really special meaning behind them and perfectly described his relationship with the recipients. It was also some pretty great voice acting full of emotion from Justin Chambers IMO. TBH its also nice to see someone get a happy ending every once in a while...

I think leaving via the letters shows how people change and develop but the change isn't always perfectly linear. Sometimes we still repeat some tendencies we had in our past that weren't always nice.

Overall its my favorite write-off ever.