For my short 1 night stay with my partner, everything was good. The room is small (as to be expected in HK) but that wasn't a problem at all, it was clean, comfortable and has everything you need. Although if we had our large suitcases with us then the room might just be a bit smaller than I'd prefer.
The location is perfect, being in the centre of Mong Kok with easy transport to and from airport. We got a window room, but it only looks out to the the other rooms of the building and not the city. This did mean that it was quieter without facing the traffic and bustle outside though.
Definitely recommend this place if you plan to be out most of the time and want to come back to relax in a cozy, quiet room!