me and my friends stayed at the grida city hotel for 4 nights in the end of april-begining of may. when we planed our vacation we decided not to take a 5 stars hotel becuase we want to see the city, not to stay in the hotel the whole time. We arrived at the hotel and while check-in we asked the man in reception if he knows good bars\pubs. He was nice and offered to take us out. In the next days he showed us the city center, old city, market and beach and in the nights we went to different bars, pubs and clubs.
Bad things about the hotel: not always enough hot water in the shower, the hotel isn't close to the beach or the city center\old city: you have to use public transportation (it's called "dulumush") or a taxi.
Good things about the hotel: very nice staff, food is o.k. (if you're not spoiled), big pool.
Things you should see\go to in the city: market, marina, "duden falls" (we took a boat ride).
If you can find yourself a nice local-man\woman to show you the city, like we had, it's the best thing you can do because this way you'll see all you should see in the city, and won't need to pay a tour-guide.
Recommended not to go in the spring time: the whether was nice and hot but the water in the pool or beach was too cold (about 17 c). some people did go in the water – maybe it's because the come from cold countries… we are from Israel so we thought the water are too cold… :)