Just returned from Krakow, stayed at Modern View Planty Park, unit 26. Yes, the reviews about the trams with noise is true. We did sleep with the window open and could sleep OK, as the room got kind of stuffy. Trams start about 4ish in the morning and end about midnight. The unit was clean, no complaints. Only complaint is the shower bottom leaks water all over the floor, had to maneuver the shower to spray to the side wall to avoid water all over the floor. Poor installation of shower door with no sealant or installed wrong. The TV, somehow had only 1 English Channel, could not turn to any other station, was fixated only on that channel.
Location is perfect to the Town Square, plenty of good restaurants, try the “Bar Mleczny”, but bring google translate.