I was pleasantly surprised that the kids can use them, and I expected them to be drone like so that was no surprise for me. That aspect of familiars was pretty clear from the game play preview they did before RoM released. What I didn't expect, though, was how little dialogue I am seeing from them. Once my spell caster maxed out, my familiar hasn't really said much. I actually enjoy reading the more unique notifications that the game provides, and I was looking forward to dialogue quirks from my familiars, but I honestly haven't heard much from my familiar now that I know all the spells. If I'm going to cruise around with a stylish drone at my back, at least make it a properly sarcastic and tongue flaying familiar that is going to make me snicker with maniacal delight. There are some very creative writers on the development team, so I feel like a little more witty banter from our familiars isn't too much to ask for. An option to click on your familiar and prompt an insulting or supportive comment from them would have been a nice touch.
I do appreciate them allowing cats to be familiars, though. That was a nice option that will allow my sims to have a more realistic familiar to caster relationship should I ever want one. I'm not a big fan of pets in my game, so I may never use this option, but I like knowing that it's there. I wasn't sure they would put the effort into developing it, and I was happy to see that they did. Big kudos for that!