I prefer texting to instant messaging... I don't know, there's something still so magical about getting a text... Although I love the layout of Facebook Messenger, I must say.
It depends on the context. If our friends and family are having a smart phone and aware of how to use IM apps, then it would be IM. Else, it is better to stick with texting, because old people were used to that.
I prefer texting because it doesn't depend on the other person already being on some secondary thing. If they have a phone, i can reach them, and if i don't feel like using my phone i use pushbullet.
I prefer the way apple does it with iMessage (technically IM) how if the other person has an iPhone or iDevice it automatically sends it via internet but if not it sends it through text message. This method makes it so that the way you send messages is seamless.