I can't tell you what to do, I've done both and what I do depends on a lot on what is currently going on in the home as well as my cats' personalities. This is a list of the questions I go through when considering the best situation for my pets.
What is the Health of My Cat?
Generally, any cat who is ill (with either an acute or chronic condition) should be housed where they will be observed 24 hours/day (a cattery). Even a chronic condition that is well controlled while you are home can quickly deteriorate (especially if the cat is stressed over your absence).
How Well Does My Cat Accept New Situations?
If your cat is upset by any travel or new situations (for example, Hunter HATES going outside with a harness because outside is unfamiliar), then they are probably better off staying at home with a caretaker.
How Well Does My Cat Know the Caretaker (and Vice Versa)
If your potential caretaker (neighbor, family member, paid sitter) knows your cat well, then you may feel more comfortable leaving your cat at home (especially if the caretaker is familiar with cats). The caretaker will be more likely (than a stranger) to notice a change in personality of your cat that could be indicative of a problem. A cat who is comfortable with the caretaker will be more likely to socialize with the caretaker, so the caretaker can ensure that the cat is okay.
These aren't hard and fast guidelines. For example, I had a cat who was finishing an antibiotic for a respiratory infection but decided to hire a professional pet sitter since everyone would be more comfortable at home. We had hired her for several previous trips, so she knew everyone, and she was a veterinarian technician (and had 6 cats of her own) so I felt confident that if something happened, she would see the problem and know the best thing to do.
On another trip, one of the cats was sick so I felt she needed to be boarded. She HATES new situations (they terrify her), so we boarded her with her best friend to ease the stress (and her buddy was super easy and didn't mind anything).
The main question to ask yourself is If there is a problem, will my cat be cared for? and make sure that you leave your cat in the best situation to get the care they need.