I booked this apartment at short notice for a business trip. I stayed in 503. Pros - great location in old town (5 mins walk to famous clock !), restaurants and pubs nearby. 5 mins to trams and Palladium. Spacious, working facilities and appliances. Quiet (double glazed windows). Fantastic support from the apartment staff. I had to extend my stay and they quickly found me another apartment downstairs.
Cons - comparatively more expensive than other AirBnB but cheaper than equivalent hotels. They are some pubs nearby and you can expect drunkard tourists on the street but it is safe. Pillows are too soft, bed way too hard. TV channels are all free - which means very limited choices for English speaking individuals. PS very good Japanese restaurant just downstairs
In Summary, choose it for its location - convenient for business and sight seeing