A Cavalier cross is far more likely to have health issues than a well sourced Cavalier.
Cavalier crosses are puppy farm gold, I don't believe there is a single reputable breeder of a Cavalier cross. They either don't fully health test the parents (Cavs are particularly expensive to fully health test because of MRI needed, as well as DNA tests, frequent heart tests, etc) and/or the breeders don't know their lines well enough (essential to get a healthy heart, since you won't know about the parents heart's until after litters have bred and you need a long line of heart healthy to have the best chance at avoiding issues).
Most cavalier health issues are also a problem in breeds they are crossed with, so you won't prevent health problems by crossing, just pretty much guarantee to support either a puppy farm or byb.
Cavaliers are wonderful dogs (I have a Cavalier and a show type Cocker). They are very much a happy go lucky dog. They love everyone and everything (the hardest part of their training is to stop them running up to strangers or following other dogs, when off lead). They are very forgiving dogs and a well bred one should never be snappy or growly. They love fuss and attention.
They are very much lap dogs in the house. But very energetic and a spaniel outside (something a lot of people don't realise because Cavs are so often kept obese and under exercised/unfit). They need an hour of walking, mostly off lead and will go all day if you want. They make perfect family pets.
They are also very low moulting (what they do mould pretty much all comes out in the brush - I don't get hairs around the place from my Cavalier - although a lot of people involved in the breed say they are worse once neutered)