Just got back from Mallia Residence, stayed 3 night during long weekend in Rome. The hotel is on the ouskirt of the city, but very good to reach by public transport. Just next to train station Baldiuna (you are in 1 minute from train in your room). Room was clean, big enough and clean, confortable, much more than what we have expected. Nice reception, helpfull stuff. Small, well equiped kitchen corner with fridge. Our room in basement had a large terrace. Cleaning every day, we have nothing to complain about.
Booked via hotels.com, for 200 EUR / 3nights /2 persons is great deal.

Some tips about how to get there (sorry for wrong spelling of italian names):

From Fiumicino - take FR1 train (5,5 EUR/person one way) to Trastevere, change the line to train FR3 direction Viterbo. You will be in hotel in some 45 mins max, with just one easy change of the train - and you are, as mentioned above, in one minute in hotel from train station Baldiuna.

To Vatican - St. Pietro - Take train FR3 just 3 station to S.Pietro station, 5 mins walk to church

The train operates every 15 mins in work days (maybee less in evening) and every 30 mins in weekends.
When traveling to/from airport, take a train.
When traveling from hotel to city, take a train + metro
When traveling from the city back to hotel on WEEKEND - go to Lepanto (metro B) station and take a bus 913 in direction Baldiuna - go out at Baldiuna station (a sqare Baldiuna) and walk just 5 mins to hotel. This connection is much quicker, trains operates only every 30 mins and if you miss the train, you must wait.
When going back from city on work days, take the combination of metro + FR3 train - do not take the buss, there are trafic jams and it will take more time to you.

Have a nice stay!

P.S. When visiting a Vatican museum and you are not planning to spent more than 3 or 4 hours, it is good to go there around 2 or 3 PM, there are no ques (We came at 11 AM and was waiting 1 hour, when leaving at 2 PM, there was no que!)

Just returned from a 4 night stay here - 2 of us -50+ ladies and we can only praise this hotel. Accommodation was even better than expected - so clean and comfortable and what a bonus the pool was! Paying 3 euros for a bed is ok. As it was August many shopkeepers go on their own holidays and combined with it being a residential area there's nowhere to go in the evenings so that could be a drawback depending upon how you wish to plan your day.
We stocked our fridge (nearby corner shop)and were quite happy on the balcony after a long day in Rome! The restaurant on site is very good. Metro is right next door but quiet. Turn right as you come out. We comically turned left when we arrived and sat and had a cold beer at a corner cafe and then asked the owner where the hotel was. As he pointed and laughed we realised that we were only a few feet away!

The room was quite big and clean with efficient air conditioned, nice also the swimming pool (free entrance asking the ticket at the reception, but 3€ needed for hiring the one of the beds by the pool).
The only problem is the distance from the city center. Trains in the near-by station (20m) are not so frequent (about every 40 minutes) and so is the bus service (about every 30 minutes). In both cases you have to change as these don't go directly to the historical center of the city and the service stops around midnight.

We are a young couple in our 50's, and stayed at the Mallia for 4 nights. The hotel is efficently and professionally run. We had a 2 room suite with lovely furnishings. The place was very clean and the housekeeping above average. The staff is polite and helpful. We enjoyed the decor of the breakfast room and the breakfast itself. It was a buffet breakfast - as much as you want of everything. Included: coffee and juice ,appetizing pasties and doughnuts, salamis, cheese, yoghurt, fruit salad,cereals, toast and more.
The pool is very big, but also used by the Mallia Health Club. Therefore although we enjoyed the pool, it was quite crowded. The hotel is right next to the train station, which is very convenient.