Hello OP, I have a Bichon Frise/Shih Tsu cross, she is a rescue so I haven't known her for her whole life, only since the age of four.
First of all, my biggest fear about purchasing one of these dogs is the fact that they will no doubt be attractive to the very worst kind of breeders, puppy farmers and unscrupulous, inexperienced breeders, with all the abuse and horrendous treatment of the breeding bitches and the puppies, that goes with that territory, because they are so friendly and appealing and the breeder will just see ££££.
They are prone to quite a few health problems, like many small breeds, including, hip dysplacia, luxating patella, cataracts, retinal atrophy, eye infections and bladder infections.
Having said that, I have found her to be charming and a very easy rescue. I have never had a small dog before, am an experienced staffie and lurcher owner, but she has really impressed me. She is very clever, so easy to train & obedient, she is sociable with all dogs, of all sizes, very calm and independent, great recall. I walk her at least twice a day, off lead, in the woods or fields, for 45 - 60 mins each time, with an extra short walk last thing at night. When she is at home she is happy to curl up and sleep or potter around the garden. She is happy to be left alone, never barks, at passing dogs, cats, people, cars but will alert me to people at the door with a few loud barks, before stopping as soon as I open the door.
She is 10 now and she does have a luxating patella but it has never required treatment and it doesn't bother her, she also has cataracts, but she has taken them in her stride.