I was traveling with a friend and we knew that in Vienna hotel prices were prohibitive. However, on expedia we found a good deal for this hotel (around the 55 euros per night) and we did not hesitate. Some of the reviews had said that the hotel was noisy and the walls paper thin. I guess since we stayed there in the winter, when there are less tourists, this was not an issue for us.
The staff was incredibly helpful. The price included WiFi, and we were able to print a couple of pages at no extra cost. They also have stamps and you can drop off your correspondence at the front desk and they will mail it for you.
The room (in the red section) was basic but quite spacious. The mattresses were good. Perhaps a bit more light would have been nicer, but the room was spotless clean. When we booked, we did not have the option of twin beds, and upon arrival I asked whether something could be done. The girl at the front desk apologized and said she was not strong enough to go up herself and separate them, and that she would leave a note for housekeeping. It was not necessary as we had no problem separating the beds ourselves, but it was nice of her to offer. My friend said she experienced some problems with the temperature of the shower (too cold) but by the time it was my turn this was not a problem. Perhaps it takes a while to get the water warm.
The television in our room for some reason did not work, but we didn't miss it, there is so much to see and do in Vienna we were barely ever at the hotel. We never reported it, but I am sure they would have fixed it, had we asked.
They offer free drinks at the lobby included in the price and the buffet breakfast is 15 euros if not included in your reservation. If you have time perhaps another Viennese cafe is a good opportunity to experience local cuisine (although the price difference is not that large), but for us it was handy to have this breakfast before catching an early train. I have a gluten/lactose allergy and there were enough fruits, salads, eggs and other products that I was able to eat (the bread is in a different section).
As for location, this is barely outside the Inner Stad ring, but it is a walkable distance to the center, it is literally on the street behind the museum quarter, and if you don't feel like walking there's a quite good transit network 2 minutes away (Volkstheater stop). It is very easy to get to the hotel from the airport and it was also easy to get from the hotel to the Sudbahnhof, where trains depart for Bratislava. Tickets for public transit are not difficult to procure, and they are not expensive either.
We did get a good deal out of this hotel, and I would definitely stay there again.

The staff were all extremely helpful and the room was very clean and neat. Nothing fancy but who cares? It's 2 minutes from the tube, 5 minutes walk from the museums and 15 minutes walk to Stephansplatz. Free WiFi too (daily password, just ask reception).
It had the very rare bonus of an actual double mattress (do married couples not stay in Vienna?) although still single duvets!
If you don't want to pay 15 euro for breakfast go left out the door and left again and there's a couple of places doing breakfast for about half that.
Staff recommended the Siebenstern brewpub / restaurant on the street of the same name (right out the door and follow the road to the right for 5 mins) which we liked - lots of beers and big pieces of dead pig.
Would definitely recommend.

It was such a refreshing change to finally stay at a hotel which has given some consideration to what will make their guests happy.

The location of the hotel is excellent. It is a few steps away from Volkstheater train station, or an 11 euro taxi ride from Wien HB. Vienna is a very easy city to get around, and this hotel is within walking distance of all of the main attractions (like the winter palace, the spanish riding school, the albertina, Statsopera etc etc).

The first thing you notice about Viennart is the grand lobby. It really gives the appearance of an excellent hotel, although the decor is rather different (in a good way). The rooms are also excellent. The bed was very comfortable, the shower had good water pressure and temperature control, and the TV had English channels (the usual - CNN, Eurosport, BBC World).

The highlight of our stay at Viennart would have been the free juice and coffee. It is a really nice touch. The coffee is actually quite good - the latte macchiato is just like one you would pay 4 euro for in a cafe. However, be warned that the machines are turned off and cleaned between 11am and 12pm. We would have saved 10 euro per day by having coffee and juices at the hotel easily.

We did not have breakfast at the hotel, as we thought that 15 euro per person was far too steep (usually, you could expect 5-8 euro). But from what we saw, the breakfast looked great.

Nearby, heading towards the ring road, we found an excellent restaurant called 'Belleri' (?). The food was brilliant, as was the atmosphere - with the resident pianist.

All in all, this hotel would be an excellent choice for your stay in Vienna!

I went this hotel for 3 times and no regrets:)it is very clean central hotel you can go to metro station by 1 minute walk.There is always free coffee in the lobby.We didnt eat there just used the hotel for sleep so no comments.Prices are ok.The last time i visited with my family on a really rainy day we were all wet and went to hotel but there was no room avaliable.But they were really helpful so we checked in a suit for a very reasonable price.