Overall, this is a nice place, but it may surprise people who are used to cushy hotels.
It seems the Korumar is designed to suit Germans. There were Germans everywhere. It's set up for orderly tourists who don't mind Spartan facilities and like to have things planned.
Our standard double room was half the size of our rooms in Istanbul. The "double bed" was two twin beds jammed together. There was only one sheet on the bed, and the spread was a small cotton blanket with holes woven into it. My wife was aghast and demanded two more blankets.
The hotel had one soap dispenser on the wall by the sink, and there was another on the shower wall. Our dispenser was empty, and it also fell off the wall, but the Korumar sent help immediately when we reported it.
The buffet food was institutional, like the food in a college dining hall in America.
The dinner items were acceptable; they kept us alive. The desserts were better than everything else. The impression I got was that budget-minded Germans went to the hotel for food that was inexpensive and abundant, and they weren't concerned about the taste.
At night, we heard drunks talking and laughing loudly on nearby balconies.
The staff was very friendly and extremely helpful. If you need local information, they will provide it with a smile.
If you don't mind a little austerity and food that may remind you of your military service, the Korumar will make you happy, as I was. My wife, however, says she will never go back.