Beautiful place, in a central area, close to historic places of Rome (which are everywhere). Or room was small-ish but very comfortable, the bathroom and shower were fantastic.
Hotel staff, are very nice, helpful and always trying to help with a smile on their face.
The nearby avenue is busy at times, but we were at walking distance of many nice areas, including (a little longer walk) the Coliseum.
We were in January last year. Weather was fine, you can make do with a shirt, jersey and a light jacket.
And best of all, although there were plenty of tourists, our was nowhere near to what there are in summertime.
And, room prices at Barberini were probably half or less of what they are in summer.
Highly recommended, and I warmly recommend to visit Rome (and Italy) in winter (maybe Milan could be colder, the rest is really fine weather, less expensive and not packed at all (except Rome, and still is half-packed)