I rented a room at the CABINN City Hotel from 27 February to 02 March 2023 and can generally report positive things. The rooms and especially the bathrooms are very small, but for the price per night you can't expect a suite.
The only thing I found really annoying was the toilet. I know that Copenhagen is a very environmentally conscious city that wants to set a good example in this respect. However, I find this effort exaggerated when the toilet flushes so little water so gently that it has trouble flushing down a single(!) piece of toilet paper. Unfortunately, this is not an exaggeration. I usually had to flush several times and let the flush fill itself over and over again to somehow flush a single piece of toilet paper down the drain, let alone more than one piece. Environmental protection deserves honour, but you can't live like that in the long run, especially when you're pressed for time. I think that the bathroom also had no ventilation, so the only way was to open the window in the bedroom for a while to get the water vapour out. The hotel staff was very friedly and the rooms were okay regarding the price, but the bathroom was a real pain in the neck.
Nonetheless I would recommend the hotel for short stays, because of the price and the top location near the main station.