I was in Prague in October 2010 for the Czech Republic - Scotland football match in Prague. This was my first time in Prague, and had no idea about the layout of the city, but looking through trip advisor, Hotel Otto got good reviews and was in my budget.
I arrived at the hotel at 11am, but was told to come back at 2pm, and though I asked about using an empty room (even if untidy) to freshen up (as I had been traveling for 12 hours) it fell on deaf ears and was told "at 2pm!!!".
Hotel location is alway from the tourist traps of the city centre, but is located down a few seedy looking back streets away from any life (after dark I would normaly hurry to get back to the hotel).
Another thing is, the front door of the hotel is ALWAYS locked, so you have to ring a door bell to get in. This is ok during the day, but at 3am when it goes off every 5-15 minutes, it does get VERY annoying!
Breakfast seems to be a mixture of continental and Easter European (warm and cold selections of meats, eggs and cheese) with juce, cakes and coffee... may not seem much, but enough to fill you till lunch time (which is a good thing as the food on offer in Prague is to die for).
Staff in the hotel can be a little rude, as the first night I came back at 2am, rang the buzzer, and got a rude reply of "what you want? no rooms!!!!!".
There is a metro station about 5 minutes walk away which gets you into the center in no time, but a taxi from Wensislas Square will depend on what taxi you get. First night I got an offical taxi, and it cost £5 (on the metre), 2nd night I got an "unoificial" with a rigged metre and the same 5 minute journey cost me £20!!!!! The drivers will say "its on the metre" but try get a rough price off them before.
All in all, not a bad hotel, but with just a little more research, I am sure better could be found.

My Wife & I stayed at the Hotel Otto in Prague on Oct 10 for 3 nights. We received a great rate 32 euro per night B&B and were encouraged by the good reviews. These reviews were spot on, as the hotel exceeded expectations.
Based a street away from the River Vltava, the hotel is a 15 minute walk from the New Town, across the river, with the Old Town and Jewish Quarters a little further away.
On the same side of the River to the Hotel is the Lesser Town and the Smichov district which boasts a shopping area for seemingly the locals.
We booked Prague Airport Transfers Ltd for pick up from the airport. They were on time and great at this (although if you book the Dinner Cruise, they will only take you one way, not a return trip, although there e-mail and internet advert states a return journey.)
Once at the Otto, we were greeted by a great reception staff (dark haired from Belarus), who was helpful and friendly throughout. The room (31) was large, with an entrance area, a sofa, TV, and everything was really clean. Safe facilities are available for 50 Czech Koruna per day. Breakfast in the hotel was plentiful, from hams, cheeses, cereal, juice, coffee/tea, toast, rolls, yoghurts, fruit as well as eggs to order and a hot plate. How can anyone not be happy with such a start to the day.
There is also a room opposite reception where you can enjoy a coffee or drinks from the fridge (to pay) as there are no such facilities in your room.
We took a walking tour on the first day (free for 4 hours). This was really interesting and showed all areas of interest in the city.
We booked a Dinner Cruise for 740 Koruna, which had a hot / cold buffet, a welcome drink and music all night, a lovely trip along the Vltava.
On the last night, we ate on the Admiral Botel, which was near the hotel. Prices on the boat, as in Prague in general were very reasonable and you could enjoy a 2 - 3 course meal with beer for £20. We ate at the Pivovarsky Dum and at the Kolkovna as well and both were lovely (although the Czech meals with dumplings and heavy bread are very filling.
All in all, a fantastic trip, the city is well worth a visit and to stay there, I would recommend the Hotel Otto to anyone who wants a friendly, inexpensive but spotless hotel near all areas.

Nothing to complain about. Really nice place, very clean, and everybody was kind and warm. Tram station 3 blocks away, nice buffet breakfast included. Would recommend it to anyone who wants to stay in Prague.

The location was alright, not too far from mala strana. Breakfast was workable, rooms basic, but not a bad place to stay. They let us keep our luggage there while we went to Cesky Krumlov. The dark haired young lady was much more helpful than the other staff. We asked if it would be possible to borrow an adaptor and the blonde lady told us that she didn't have one. When the dark haired young lady came back we asked her and she quickly produced one. If you can, deal with her only. 20 minute walk to the castle was nice. If you want a less touristy experience walk south and check out Smirnov area just south of hotel.