We stayed for 2 nights and upgraded to a room with the jacuzzi bath. The room was spotless (along with the rest of the hotel) and plenty big enough. The only fault we could find with the hotel was that they charge for orange juice with the breakfast (4 Euro).
Rome as a whole is extremely expensive and unfriendly. I paid 21 Euro for a beer and a water, and 81 Euro for a 2 course meal with wine.
The best tip I could give is buy a ticket for the Red double decker sightseeing bus (20 Euro for 48 Hours) and use it as a taxi.

When we arrived - we called the hotel upfront, to inform that we are arriving late. At that time the personnel just wished us welcome, so we took a taxi to the hotel when we arrived in the evening, but:
At the reception they told us that there had been a challenge with their it-system and they had no rooms available - the receptionist informed we had a room for 2 of the 4 nights we were supposed to stay at the hotel, and we had to go to another hotel two blocks away for the first two nights.
The hotel we were guided to was hotel Londra - actually a good hotel, we would have preferred to stay there for the whole visit.
When we two days later checked in to this hotel, the room we got (which was supposed to be an upgraded room), the room was a big disappointment:
The colors and the design of the room and the furnitures was awful, the walls were dark blue / grey and the furniture were painted with a color of gold. There were no place to get electricity to the laptop or mobile phone if you didn't choose to unplug a lamp or the television.
The cupboard in the bathroom, was damaged by the water from the shower.
There is a nice bar on the roof of the hotel, but it was open only for a couple of hours in the late afternoon / evening, and the price of a glass of wine was 7€, this I consider very expensive.

I found the website pictures to be very misleading! The rooms are TINY, TINY, TINY!! We booked this hotel for a 7 day stay and could not even unpack our suitcases because there was no dresser, no drawers, and only 3 hangers. And the minibar (which gave off tremendous heat) is in the armoire which also included the safe, thus there is no room to hang anything. The only nice thing I can say about the room was the rain shower, but the shower itself was also tiny.
The breakfast staff was pleasant, however the front desk staff was very unfriendly and cold, unwelcoming.
Also, the hotel is not located as closely to the Spanish Steps (and other sites) as the website would have you believe.
We also got ripped off by the taxi driver taking us from the train station to the hotel, charged us 20 euro, should only be 10-15.
We did not spend a lot of time in the room, however I expected much more and did not look forward to going to the hotel each night.
All in all I would not recommend this hotel.

We had made a booking through ebookers in January for our stay end of May for 5 nights. As we missed our connecting flight due to delays, we arrived a day later. After sleeping only a couple of hours in Germany we were happy to get to the hotel. However, we were told that we the hotel was fully booked, and we had to go to another hotel for a night, but that as a compensation we would get a suite for the last three nights. I was very frustrated as I had e-mailed with the hotel just a before our arrival and asked if everything was ok, as this was the trip when we were planning to get engaged. And our booking was made monhts in advance!!!
After refusing to move to another hotel, we were given tiny room of 2,5 m x 3 m and again we were promised a suite to compensate our troubles. Of course, pure lies! Our new room was just a regular room and when we asked about the suite, we were simply told that they were all full. No apologies, nothing.
One male employee working in the reception must be the unfriendliest receptionist I have ever met (around 50 years old, looking over his glasses if he even bothered to look at you). There were many examples how unkind he was, for example an elderly couple got stuck in a hot lift for quite a while (it was 30 degrees and the did not even have lights), but there were even no appologies by him.
All in all, do not choose this hotel! There must be better and friendlier options. Rome is romantic city and we did get engaged, but Hotel Veneto was just very unpleasant experience. It definetely does not deserve 4 stars, as the rooms also need renovation.