Me and my boyfriend spent 5 nights in this hotel. It was really worth the money we payed for it. First of all, it's location is good since it's close to the metro station "Manzoni" (7 minutes walk) and also rather close to the "Termini" train and metro station (15-20 minutes walk).
The rooms were cute and clean but a little small. The bathroom was rather new and clean. There was adequate heating of the room and a nice TV. Unfortunately no balconies just windows, but we visited during winter so it didn't really matter! The breakfast was satisfactory, not something special but fine (cereals, yogurt, bread, cheese, ham, honey, marmalade, coffee, tea, milk- I think they should have some fruit and vegetable).
There was a bit of noise since our room was at the side of a rather busy street, but not something very annoying. The only problem I would point out is that there was not a double bed as we had asked but two single beds put one next to the other.
In general I would recommend this hotel as value for money and for its rather good location.

In former reviews I read about rude staff members in this hotel. Well, may be they are not working in Hotel Parker anymore, because we only met friendly and helpful staff during our 3-night stay.

The room was spacious and clean, so was the bathroom. Towels where changed every day. Breakfast was served in the basement that had daylight. There was a lot of bread, cheese, meat, jams, yogurt and cereals and of course coffee machines for all kind of different coffee.

Getting there was very easy. We took the Leonardo express from Fiumicino airport to Termini Station, but the train ends at Roma Lazialli station. To get to Termini station you have to walk about 300 meter, but the best is to leave Lazialli station on the Via Giovanni Giolotti side and then take the tram that is in front of the station. Get out at the first stop en walk about 200 meter.
Traveling into the old town, we walked ca. 230 meter to Piazza di Porta Maggiore. There we could find a lot of buses and trams to all kind of different destinations.

The only minor was the absence of WiFi for the guests. I think that every hotel or Bed&Breakfast have to have this service nowadays.

But overall, we had a nice stay in this good budget hotel.

we spent 4 nights in this hotel.
the first 2 on the first floor, which was very noisy (wallpaper thin walls and noisy plumbing, plus you can hear the trains coming and going to termini station).
location:
close to termini station, you can use the metro to go everywhere - which is a plus.
the downsides are the noise, the scarry invoirment after dark that unabells enjoying a walk aroung night time.
breakfast:
pastries, bread, cheese and ham. no vegetebels or fruit. on our 4th day the juice machine went dead and the staff failed to provide drinks that day.
the hotel is very clean.
bottom line:
the rooms are very small.
it is nowhere close to a 15 min. walk to the colosseum like said in other reviwes.
i advise choosing a hotel in a better enviorment.

We have used this hotel for the last 5 trips, the rooms are clean and kept very tidy , very close to the train and bus stations, the breakfasts are good and keeps you going for a long time.
The staff are friendly and helpful, and it is great value for money.i would recomend this hotel to anyone looking somewhere to stay very close to some of the main sights of Rome.
Hope to visit it again very soon.