I use them a lot whether I want them to be happy, miserable, part of the save or just be in the background every time I think I'm gonna ignore them completely I end up using them again, like the goths speaking of I need to play today. Currently I have picked a few to add to a normal length save to move their children along faster and it's been one of the runs where I change jobs or cheat levels and skills just for something different. Which also sometimes determines how much they get made over which helps in other saves when I don't feel like doing makeovers they are almost different.
https://i.imgur.com/HioI4cl.png
Believe it or not for those who haven't seen this is Vladislaus (second makeover from my old one) and Johnny Zest, He just had their first baby and as you can see the moody old vampire is expecting the second, cause why not.