The ad states that there is a unit above, and you can hear some noise if it is occupied. While we were there, someone was in the unit above us. You hear a lot of noise from people walking around, dropping things, toilets flushing, etc. if you are a light sleeper, I suggest renting the top unit. We had our boat in Catalina as well, so we were out and about most of the day, really only used the unit to sleep and cook.
The kitchen was well stocked, everything was clean, new appliances, very nice!
The property manager , Veronica, was very accommodating and quick to respond via text messages.