We had an 8 night stay in August while in Melbourne for a conference.
The location is great and the apartment is very spacious. Good for a week long stay as there is a washing machine and dryer, lots of wardrobe space, steamers for clothes and full kitchen.
As previous reviews have said the key pick up location is a ~15min walk away (up in the north of the CBD) so that would be worth thinking about if travellers are arriving with a lot of luggage or have mobility issues.
Communication was really easy and efficient and Kelly also very kindly located some jewellery I had left behind and posted it to me interstate - thank you Kelly :)