Since all the good things for this hotel have been written , I will write about the bad things .
Shuttle bus :hotel - airport :15 euros ( we thought it was for free , it is not ), a small chocolat from the mini bar 8 euros . Keep with you the confirmation and do not accept the change in the local money and then to your currency , too much money will be lost at this transaction . And something irrelevant :watch out of taxi drivers .

The hotel was clean and the rooms adequate. The location was ok, in that it takes around 15 min by tram to get to the old city. The area is however noisy. So if you have trouble sleeping with street noice i don't recommend this hotel. The advertised that there is air-conditioning, but this is only true for the hallways. So either you keep your window open at night or suffer from the heat. Outside temperatures were around 16 -20 degrees C, but inside with the windows closed was 26 C. The staff refused to change the airconditioning from heat to air-conditioning and they can't have both.
The breakfast was very good, and eating in the restaurant at night was also good, with prices around 20$ per person, not including wine. Even a pizza is that price.
I would recommend finding a hotel in and around the old city, in a quite area. Sauna is only open until 6 at night.

Our tour group stayed at the Holiday Inn for three nights. Our twin room was comfortable but small. There wasn't much available space to keep our luggage out of the way. Room and bathroom were exceptionally clean. Great water pressure. No problems with fluctuating water pressure in the mornings!

Being New Year's weekend, we did experience some noise from fellow guests.

Breakfast buffet was quite extensive. A wide variety of breads, sweet rolls, fruit, yogurt, cheese, olives, meat, potatoes, juice and other beverages was available. There was so much food available that I didn't have an opportunity to try the made-to-order omelets.

Our group did have one negative experience. Earlier, we were warned that the one Lira coins resembled the one Euro coins. Our first night, after we checked in, a member of the staff approached one of us in order to exchange his handful of "Euro" coins with a 20 Euro bill. Our friend quickly glanced at the coins and agreed to the exchange. Later on, she discovered there were a few Lira coins mixed in with the Euro coins. Lesson learned...closely examine the coins and don't be so trusting!

Had we made our own travel arrangements, there were other hotels that we would have stayed at. Not a bad hotel. Just be careful of staff members wanting to exchange money.

There are so many fine choices of hotels in Istanbul, but we were glad with the Istanbul Holiday Inn City, not the one in the Marina area of Istanbul. Why?
1) tram in front of hotel takes one to Grand Bazaar area, Aghia Sophia, Topkapki, even the airport. Some hours there's a crush on the tram, but it's usually fast, efficient, clean, and people are polite offering a seat to those in need of one.
2) breakfast buffet which is included in many rates is varied, good for the first few days.
3) Rooms facing inner court are quiet, even if they're smoking rooms - our two rooms were smoking but smoke free inside. It's the rug freshners in the hall way that may tickle or burn your nostrils sometimes.
4)no peeling paint, everything worked well, the air con, the heat, no tacky rough edges. It doesn't look like a Holiday Inn - it's in an old, architecturally intersting building.
5) not in a tourist area -= nearby neighborhood is fascinating, there's an open air market that fascinates, lots of restaurants and stores - we relished the food, bakeries, shopping, sights and sounds. The Barcelo hotel is across the street.
6) Internet access is available in the room - with access via a card one buys for either euro 5 for one hour or euro 19 for 24 hours - unfortunately they ran out of 24 hour cards - a major hassle.
7) Guests are mostly European, staff is decent; we felt safe though in a chain that typifies USA - Turks we encountered werfe muc more cordial to us than in Greece, for example.
8) Cute hotels in other parts of town are chaming or large and offering more services - but we felt very comfortable with this choice - this Holiday Inn is not too big, not too small, reasonably priced, BUT don't eat at the restaurant or bar at night - prices are very high for average quality. One med, mediocre pizza ab't $17 - glass of local raki - about $6 We were concerned beforehand that a week in Istnabul would be too long, but there were no freq. flyer seats available to return home - but it turns out there was so much to experience in Istanbul - we love it.