Good beach base, rough as an actual hotel.
The location is the whole story here. You're right on the Black Sea beach, which is lovely, but despite the name it's NOT convenient to Istanbul Airport. It's about a 30-minute drive with several tolls to reach the actual terminal entrance. If all you want is somewhere to shower and crash after a beach day, it does the job.
Beyond that, I'd look elsewhere. Check-in was a hassle. The room and shower were small but adequate on their own. The problem was there's almost no floor space beyond the bed. For two people, one of us had to climb over the other to get in and out. We travel light with just carry-ons, and even so there was barely room to stand once our bags were down.
Cleanliness was hit or miss. Our room was moderately clean but we got only one towel and no cover on the bed. When we checked in at 5pm, the other rooms were mid-clean with mops and buckets everywhere. Ironic, given all the signs warning you not to track sand into the hotel.
We ended up leaving for a place closer to the airport. Fine for a quick beach stopover, not for an actual stay.