We went to the Candeo Ueno hotel in April 2012. The hotel is situated 100m North-East of Uguisudani JR station, on the Yamanote Line: take the South exit, cross the tracks, go down the stairs and turn left on Kototoi Dori. There is a good and very cheap Yakitori shop for locals at the bottom of the stairs (be careful, some skewers are made of offal). The area around the hotel is peppered with slot machine and "massage" places, with a few love hotels for good measure. It is however safe, probably because there are a lot of commuters most of the time and also a few more normal businesses providing for the locals.
The hotel reception is on the 2nd floor (reached by lift or stairs). Staff are efficient and have a sufficient knowledge of English, although they do not seem overly keen to help, but this could have been down communication problem, since we didn't speak Japanese.
We booked a standard double (stated at 16m2), non-smoking. Our room was on the 4th floor and offered absolutely no view, except the back of a wall. There was some daylight light coming in, though, and it was quiet (no train noise). The room was on the small side but not more than what could be expected for a business hotel. The room was clean and the decoration was OK and quite recent. The bed was probably 120cm wide and was comfy. There was a narrow desk, with a LAN cable (free internet connection). The bathroom was simple (sink, electric toilet, small bath tub with shower handset) but clean and in good working order. The room had a kettle but the tea/coffee and other amenities are to be picked near the reception desk. The green tea was good (powdered). The TV was a decent one, with free Japanese digital channels. There was also one of the ominous vending machine (mainly drinks) near the lift. The lifts were quite new but there were only 2 of them and they were very slow. We didn't have breakfast at the hotel.
Overall, this is a good business hotel worth considering if you are on a budget. It's location is really convenient on the Yamanote Line, just one stop away from Ueno JR and 10 minutes from Tokyo JR. One could probably walk to Ueno JR. I rated it "Average" rather than "Very good" because the area will not be of everyone's taste and our room was the smallest of all the business hotels we tried in Japan, but the rating should really be in-between; it is Tokyo after all. Comparing with other hotels we used in Japan (low season), the last minute price was within average for this standard, but there are good deal in advance booking if you stay a few days.