We stayed in Olivia's apartment for a month. Will quickly summarise the pros and cons as we saw them.

Pros:
* The location is great - easy access to the city, Manly and Balmoral. Mosman is a pleasant area itself too with plenty of nice shops, restaurants and cafes
* Spacious - plenty of room for a 1bd
* Functional - the apartment is equipped with most things you'll need for your stay, including a washing machine and dryer which really come in handy
* Natural light - we didn't need to use lights much as most rooms have skylights (windows in the ceiling) - saves energy and feels good
* Reasonably priced

Cons:
* No aspsect/view - the building is wedged between two other buildings, so your view is of a wall - such a shame in a beautiful city like Sydney
* Questionable privacy - windows look directly out onto the main walkway of the apartment block and there are no curtains, only very minimal blinds that don't do a great job
* Light in the morning - no curtains means it's bright in the morning, so not great if you want to sleep in
* The toilet is designed such that if you use it you'll either spend time every day cleaning it or feel like you're in the 3rd world
* Shower is dodgy - had many lukewarm showers and water volume/pressure was frequently insufficient
* No cleaning service/tools provided - after a week or so things start to look and feel pretty grotty
* Insufficient guidance from the host - we couldn't find the place (the directions we received were incorrect), couldn't connect to the internet, didn't know how to dispose of rubbish, didn't know what state to leave the place in, etc etc.. so we had to ask about everything, making things harder than they should be
* Olivia is not always helpful and is extremely inflexible - often hard to contact, failed to answer many of our questions from before we arrived right up until the moment we left, refused to accommodate any custom arrangements and then demanded that we let other prospective guests in to see the place despite us not wanting to do so (when it was clear we had no choice we spent several hours cleaning and tidying the place up to make it look respectable and weren't even thanked for it in the end).

We were kind of glad to move on, but that said, you may find it fine for your needs, depending what you're after. We ended up extending our stay several times because we wanted to avoid the hassle of moving and despite its shortcomings it was still the best option in the lower North Shore area that was available at the time. As to whether we'd choose it again though, probably not.