I stayed at hotel Otto in Berlin for 4 nights and it was a fantastic experience.The hotel is very conveniently located in a quiet street near the Ku'damm Strasse and close to S-Bahn and U-Bahn stations, so well connected to all the corners of the city. The staff is friendly and very helpful. The room was big, comfortable and clean, but, being placed next to the reception desk, it was noisy at certain times. There is apparently a free wi-fi connection in the rooms, but it is extremely difficult to get connected to the net, so I wouldn't count much on that.

Stayed 3 nights, was a nice hotel. The room was clean, provided "freebies" nail file, shaving kit, shoe horn, sewing kit, toothbrush and toothpaste, "ladies" kit, shampoo, lotion, body wash, bottled water and fruit!
Was clean lines and contemporary decor. Lift stops between floors and there are 3 extra stair sets to reach the 7th floor breakfast area...but it keeps you fit! The lift plays bird noises which is quite fun.

Breakfast is really good, we had it included when we booked, good choice buffet breakfast, with champagne as a normal offering of drinks (no extra charge!)

Afternoon snacks also amazing, we had an a large breakfast went out all day and were able to come back and have tea, coffee and sandwiches and cakes ( all complementary) just go up to the breakfast floor and help yourselves.

Lovely hotel. Set in the west side of Berlin, so if you are going clubbing and want to be in staggering distance this hotel is not for you. However if you don't mind getting the underground then that's easy to use and cheap. 6.50€ for an unlimited day ticket for zones A+B which can be used on the U & S Bahn and the Bus as well. Also they provide free maps at all stations.

Staff were friendly and informative and even provided maps free of charge on arrival.

All in all I would visit again.

Great Charlottenburg location, only a 10 minute walk from Tiergarten. Ultra-modern, clean, comfortable. Great bathroom. Fantastic breakfast offering all you could possibly want, and well worth the €15 supplement. Friendly, helpful staff who try really hard. From midday to 9pm, complimentary coffee, tea and cake are available in the 7th floor breakfast room with a rooftop terrace - a nice touch, as is the complimentary mineral water and umbrella loans.

Stayed 5 nights at the end of September and we were delighted with our choice of this hotel. The location is first class being only a couple of minutes to the U-bahn and about 5 minutes to the S-bahn - in turn only a few minutes by train to Zoo station or Hbf. The area abounds with a wide range of bars and restaurants and Hotel Otto will give good advice as where to eat. The hotel itself is in a pleasant area, away from the hordes of tourists but still close enough to all the action you may seek. Staff were very efficient and friendly. Our room, on the second floor was very quiet and most spacious as well as super clean. Good bathroom facilities. Breakfast, in a pleasant room on the 7 floor with views to the City, was extremely good. Unlimited free WiFi available in your room. An excellent hotel. Only minor downside is that the lift stops halfway between floors, and not at each level, but this is no big deal