We have a maltese ****zu and he is great. So friendly and we never have a shortage of people wanting to look after him when we go away But at the same time he will bark if he needs to, especially when DH is on night shift, he feels like he has to protect me I'm sure. We are going to get another dog after the bub has come and planning on getting a maltalier (cavalier king charles x maltese) I've done a fair bit of research and found that the terrier in the maltese is good for alerting you but without being annoying and the cav is easier to train and very easy to look after.

Burkes Backyard website has reviews on all sorts of dogs.

All the best.