I stayed at the Melbourne Short Stay Apartments on Whiteman St as I was attending a conference at the nearby convention centre. Please note -- these are different than the City Rd apts.
The location couldn't have been better for my purposes -- a five minute walk to the convention centre.
The apartment itself was clean and well-appointed, and represented an excellent value for the location -- I believe I paid A$169/night.
I did notice that the lifts were always full of young student or very young professional types. I'm not sure if there's some arrangement with a local university. I didn't see many other holiday-maker types about.
I would say that even though my apartment was on L21, the street noise was still significant, esp the bells from the trams below. I found this sort of charming, but I couldn't say it was a quiet room.
It did however have lovely views.
The fitness centre was kind of disappointing, but the pool was ok.