Fremantle seems to be going through some changes right now, so some downsides probably won't be relevant in a few months.
Pros:
+Janet is an amazing, responsive host and seems like a great person. She also let me in early as she was already on site, much appreciated.
+There are a lot of nice restaurants and services in walking distance. Cicirellos is top tier fish n chips.
+Good value for multiple people staying there
+Close to Fremantle markets. If you arrive on a Friday/Sat/Sun it's a great place to stock up on fresh food
+Great variety of smart TV streaming services and comfy couch
+Free parking spot
Cons:
-Some construction noise at the moment from apartments being built
-No aircon in the main bedroom. The room with a single bed has aircon though
-Wi-fi is slow (1MB/s down, 4MB/s up). This can handle watching a show on Netflix but isn't reliable for video calls, or for multiple people to use it. If you need fast internet, use your phone.
-Right now central Fremantle has no supermarkets aside from an asian mini-mart. Supposedly a new IGA supermarket will be opening in April though, if not delayed... Closest supermarket is ~25-30min walk (or 15min bus).
All in all it's a functional place, and will be more convenient when the IGA opens. Still a decent spot if you plan to be out adventuring, and Janet will go out of her way to help you.