We would have given it five stars if it wasn‘t for the noise all day and night. Sure, all appartments along Flinders Street probably have the same issue due to the trains - although I guess with proper noise protection windows the noise would be much less of an issue. And yes, we read about the noise, however, it is much worse than You would imagine and I would definitely not recommend a stay if you are an international traveller and have to fight with jet lag anyway just after arrival.
Otherwise everything was perfect, well equipped appartment, great beds!, very friendly staff and spot on service; e.g. we had the shower head replaced right after we mentioned at reception that it was leaking.