Can't really comment about Villas Parade as I have no first-hand experience of them, but they do have a pretty good reputation.

As far as Son Serra is concerned, this is seven kilometres from Can Picafort, and is very very quiet. There is little there apart from three or four restaurants. Close by is the big ranch, Rancho Grande. Horse-riding, mini zoo, barbecues etc.

For anything more, you would really need to get into Can Picafort, or better Puerto Alcudia, but that would be about 15 kilometres.

I think I should point out that Son Serra's beach is mainly "rustic", which means that it is left in its natural state, so there is often a big build up of seaweed. It is cleaned but not of this natural stuff. The best part of the beach, where there isn't this sort of build up, is quite popular with naturists. This may or may not be to your taste, especially as you have small children.

This may sound negative. If you want relaxing, you'll get it. Otherwise ...

Our apartment is not far from Son Serra, and we have driven round it a few times. It is a very German village, and it has suffered from the down turn in the German economy. Can Picafort would be a good place for you to visit, but I would also recommend Colonia De Saint Pere, about 10 kilometers away in the other direction. It is a nice quiet village, with a small but lovely sandy and clean beach and several sea front restaurants (and a Spar supermarket too).