I have just come back home after spending a whole week at this gem of a hotel.
The staff were fantastic, they were approachable and friendly and ready with tips of what to see other than the Colosseum, Roman Forum in the immediate vicinity.
St John of Lanterne is a 15min walk away (Bishop of Romes's Church - the Pope), the Holy Steps are nearby as well, then there is the a hidden gem in St Clemente Church only a couple of blocks away - here you see the excavations of a 12th and 2nd century church under the existing one.
The hotel room was large and spacious. I was in 101 and had a great view of the Colosseum.
Air conditioning was fabulous.
The bathroom was also spacious and as a larger person I actually found the shower size adequate.
I ate at the hotel restuarant the first evening and the food was mouth watering. You do receive a discount once they know that you are a guest.
Location to the Metro is only a 5min jaunt down the road.
Taxis are close by.
Buses too.
I walked alot around Rome and found it comfortable walking to Vatican City, Piazza del Popolo etc.
You can't go wrong with this hotel.
Tip: If coming in by train. Once outside the station turn immediately left and walk to the traffic lights.
Cross the road and head for where the outdoor restaurants are.
Royal House Hotel (Royal Art Cafe/Restuarant) is on the actual corner. Just ask the waiters and they will direct you to the reception area.

So glad I took a chance on this hotel! I was looking for a triple and came across an old review of this hotel. I was not able to find many other reviews, but I decided to take a chance on it anyway. The location is perfect for touring--directly across from the Colosseum. The view from our window was fabulous! We were in room 203, which had a queen (not for sure of this size) bed with another bed which appeared to be a futon which had been folded out to full size. The room was a little cramped with both of these beds in it, but it was definitely doable. Loved the bathroom...very big with ample space for toiletries, and a nice-sized shower. My only disappointment could be in the breakfast. They only had cold cut meats and cheeses and juice on both of our mornings, as both mornings we were too early (8:00-8:15a) for the croissants which they stated were in the oven.
The staff was very nice and accommodating.
(We only ordered a pizza late one evening while sitting outside looking at the Colosseum in all its night-time glory, and it was just OK.)
It had a bit of a bed and breakfast feel to it, as it was small and intimate.
There is a taxi stand less than a block from the hotel, so very convenient.
(Cab to Vatican was 17E, cab to Termini was 10E)

PROS

Excellent location. Literally opposite the Colliseum and just 5-minutes walk from the Colosseo Metro station. Other interesting tourist sights (e.g. Forum, Arch of Constantine) are very close too.

Nice big room. Comfortable bed. Big bathroom with bidet. Small but adequate shower. There are two floors of rooms, all very nice I believe. No noise whatsoever. Excellent aircon.

CONS

This is not advertised as a hotel on the side of the building. It says "Royal Art Cafe" on it, and it is mainly a cafe/restaurant. So don't expect taxi drivers to know where it is if you say "Royal House Hotel". Best thing is to get to go to Colosseo Metro station (if single traveller, otherwise take a taxi.) It is on Piazza del Colosseo - although my taxi driver even pretended he didn't know where that was!! Make sure you have a Google Map printed.

No elevator, so not good if you have mobility issues. Breakfast was very basic but I gather this is common in Rome's hotels.

We just stayed at the Royal House for 2 nights with our 2 sons. We were very pleased with the size of the room. We had a family room for 4 people which was quite large with 2 adjoining rooms. Our bed was quite comfortable but the pull-out bed for the boys was quite uncomfortable as it was just a thin little mattress on wooden boards. The bathroom was also large and clean. We did not have a direct view of the Coliseum from our window but we could still see some of it from our window at the side of the building.

The “rooftop” terrace (which is actually on the roof of the restaurant and is on the second floor) seems to be under construction so it was closed which is too bad because it is directly across from the Coliseum and has amazing views. There is free Wi-Fi throughout the building. The staff was all helpful and friendly.

One small concern we did have is because there seems to be a large air conditioner somewhere on the building, the room had areas where a very large vibration sound could be heard. The air conditioner seemed to be turned off at about midnight so the noise wasn’t all night long and we were able to move the bed into the middle of the room so that the noise wasn’t as loud. I think it is just because of the shape of the room and the plaster on the walls and it wasn’t so loud that we couldn’t sleep.

The windows in the hotel have recently been replaced which is good as there are bars at the side of the hotel and people were up until almost 2:00 am. We could not really hear them from our room but they could definitely be heard in the washroom which has an old windo.

The breakfast was fairly basic but it did have a selection of 2 meats and cheese along with a hot croissant and coffee.

The location is fantastic as it is right across from the Coliseum and it is a short walk to other sites such as the Forum, the Pantheon, the Spanish Steps, etc… We did actually walk to the Vatican from there but it is a long walk and for 1eu you can take the metro which is just across from the Coliseum.

We took a taxi in and out of Rome. Beware that you get a taxi from a taxi stand because if one is called for you, they start the meter as soon as the call comes in. It should be 40eu from the airport into Rome.

We did not eat at the hotel simply because we never seemed to be near the hotel when it time to eat. They did tell us that if you stay at the hotel, you get a discount at the restaurant but I am not sure how much of a discount. The food that we saw people eating looked very good and the prices seemed in line with other restaurants in Rome.

We would stay here again because of the location and the size of the room.