A few more observations about this set:
Both toddlers and babies can be changed at the table, which will raise their bladder need to full. Sometimes, however, they let fly in their parent's face, causing the hygiene needs of both parent and child to drop. If this happens, the baby/toddler can get a negative "diaper rash" moodlet. Both toddlers and babies can also get the positive "powdered" moodlet randomly after being changed, which is pretty cute.
There are a couple of problems with the set. Firstly, the change/bathe interaction ends with the parent putting the child down on the ground afterwards. It can't be cancelled, and it cancels out any actions you'd lined up involving that child afterwards (eg, if you wanted to feed the baby after its bath, you'd need to wait until it was on the floor before selecting the action, otherwise it would get cancelled). I don't know why the action was programmed this way, but it gets annoying. Another irritating thing is that if you have a baby or toddler in the high chair or swing, and you tell the parent to change/bathe a different baby, they'll go to take the other child out of the swing/chair first. This also can't be cancelled without cancelling the entire bathe/change action. I'm guessing this is a weird glitch of some sort. You can get around it by having the parent hold the child they want to bathe before selecting the bathe interaction.
A final annoyance with this set is, as I said above, that the toddlers seem obsessed with asking their parents to rock with them. For this reason I hadn't used the baby monitors much, since it means micromanaging the toddlers to keep them otherwise occupied, and I prefer to let them do their own thing. But I used them again today, so I could try out the new patty-cake interaction (which is actually peek-a-boo). I realised that you can just turn off any monitors you don't want in use at the time, so you can make the toddlers play together, then switch off the monitors so they can't keep bothering the parents. Also, the peek-a-boo is fantastic - just like when a child does it with a toddler, it raises their relationship really quickly. My toddlers went from having zero relationship to being best friends in about an hour. So, even though there are a couple of problems with this set, they're easy to get around, and the awesomeness of the new objects definitely outweighs any negatives.