We've read the negative reviews, and have a hard time correlating them to our experience ... we arrived in Rome tired and worn out and the hotel was completely accommodating and helpful.
We found the hotel to be so very convenient -- close to the Termini station, but also walkable to the ancient sites, which we walked to without too much trouble (the Colliseum and Forum are NOT that far away!) I have severe knee problems, and I was able to do it without difficulty.
Our room was very, very nice -- much bigger than we thought it might be -- and the bathroom was luxurious, although strangely without a shower curtain. Our only complaint was that the water out of the bathroom faucets was not potable -- something we found out only AFTER we drank some. In Rome, this is less of a problem than it sounds, as there are free public water fountains EVERYWHERE. The air conditioning was just adequate to keep the room comfortable. Otherwise, our room exceeded our expectations.
We thought we got a great deal on the hotel and were very satisfied. In fact, we tried to change our reservations to stay the whole time at the Madison (as it was so much nicer than we expected) but were not able to as it was booked.
Breakfast was very good -- I especially enjoyed the yogurt, granola and coffee -- all of which were wonderful.
It's true the halls are somewhat of a maze, but we thought that was fun, and not at all dark or scary. The neighborhood is what you would expect 50 feet from a train station, but we didn't find it scary, either -- you just had to keep your wits about you. We heard NOTHING at night -- our room was well-insulated.
Overall, our stay at the Hotel Madison was a good one, and we would not hesitate to stay there again.