We stayed at the Adina Hauptbahnhof for 6 nights in December and were very happy with our choice.
The Adina is located an easy 10min walk to Hauptbahnhof station (main train station) which is the hub of public transport and hop on hop off tours in Berlin.
There are buses located everywhere around the hotel and everything is within easy walking distance.
We had originally booked a studio room but upgraded for €30 per night to the 1 bedroom apartment for the convenience of a working kitchen and washing machine / dryer.
There is a Lidl supermarket 5min walk from the Adina (past the hospital) which is really cheap for all sorts of food (compared to Australia)
If you like to shop but don't like to carry everything home with you in your suitcase there is a post office about 10 minutes walk in the opposite direction of Hauptbahnhof, so you can shop to your hearts content and send everything home cheaply!
Downstairs in the alto bar they have happy hour between 5pm - 7pm on most cocktails, beers, wine etc.
They don't advertise this always in the bar so be sure to ask about happy hour before ordering drinks.
The bar is a great place to sit and relax after a day of sightseeing and we always got a table whenever we went.
We dined a few times in the restaurant, very nice food and lovely ambience. The curry wurst on the menu quickly became a favourite.
Our room overlooked the inner courtyard and was quiet, with good heating and blackout curtains.
The rooms are large and bright, with very big bathrooms and the beds are very comfy.
Everything in the rooms are clean and modern, which was great.
There was a television in the lounge room and the bedroom - you cannot plug your laptop into these televisions.
The only real downside is that you still have to pay for Internet in your room, however as far as German hotel charges go, the Adina is quite reasonable charging for 24hrs usage, not time frame.
Thoroughly enjoyed our stay here.

Me and my daughter felt like home in our Adina Apartment !
The rooms offer everything you need to feel comfortable.
The crew is very friendly.
We did`nt miss anything
The breakfast was delicious
We had asked for a silent room and we got it!
Hope to come back next year.

I stayed at the Adina for a meeting at the Charite Hospital in Berlin. The hotel was one block away. The staff are very friendly and multilingual. The rooms are large and modern with a kitchenette. Very clean and updated. The value was fantastic. While the hotel is in no way opulent, it is sleek and modern and has everything one generally needs. The location was great for my meeting but perhaps not perfect for a tourist hotel. There is little to do in the immediate blocks surrounding the hotel. A walk to the central station is at most 10 minutes and 15 minutes to the river. However there are few late night bites or bars nearby. If one is visiting Berlin as a tourist, perhaps the other Adina near the market would be a better bet as it is close to nightlife near the market and near the museum island.

We arrived in Berlin nearly two hours late due to heavy snow between Frankfurt and Berlin. By the time we reached the hotel we were rather tired to say the least. Fortunately our check in was very efficiently handled thanks to Aaron.

The room was quite large with very clean facilities and a comfortable bed.

All the hotel staff we encountered were pleasant and efficient. The only comment I would make is the charge for wifi internet. It seems a bit odd in this day and age that it is still not provided by some hotels. (This is the first time we have struck this on this current trip).

Whilst the hotel staff were pleasant, we did strike an arrogant jumped up twit of a waiter in the hotel restaurant. This type of person is not tolerated at all by me as he quickly found out and backed off.