I think the surprising death hurts me more than a "planned" death through mccc. In my decade challenge I've installed a mod which tells me who have passed away. Sometimes I've cursed when I've read a familiar name, but at least I'm informed. A few days ago I let my first ingame-born heir passed away at age 77 years, he and one of his sister were my little babies and before I've started the challenge, I could never ever let my sims die.
For this challenge I've even expanded the simdays for a year to have enough time and reduced the chance of dieing (for him only). I gave him a nice elderly life with a part of his family around him, I've let visited his granddaughter, the current heir, to spend some time with him. In the end it still hurts, he was part of my game for over one year. After the death I've checked my older savefiles to save him in my gallery, unfortunately through the changes of the savefiles, I haven't any savefile from the beginning anymore. In the oldest savefile he is still a child but almost a teenager, but at least I've could saved him now. Well, I have also many pictures of him, so I can view these whenever I want.