I had a fairly comfortable stay. It was always warm inside during the February cold. I just felt a bit isolated because there was no TV or phone in my room, but I had little time to do anything else but sleep anyway. The room was also dim and not as nice as the one pictured on the website. I believe I was in room seven.
I used the shower down the hall. There were two available. The shower on the left stopped giving me hot water, so I only used the one on the right. Very small shower (and i'm not a large person).
So why would I stay there again? It was in my favorite location plus there is practically nothing else available in that area in the same price range.
I liked the area because it felt less touristy than the Spanish Steps yet it was still close to all the sites plus I really enjoyed walking around in that part of town. The following website has some great 360 street views of the area. (images #45, #65, #71 are near Hotel Mimosa). http://www.lechiavidelmondo.it/indexphoto.htm
The clerks at the Hotel also helped me carry my bags up and down the stairs upon arrival/departure and I especially liked the night clerk, an older man who didnt speak much English but was very sweet.
Directions: A couple of short blocks Behind the Pantheon, between two one way streets, Via Monterone and the better known Via di Torre Argentina. There is a small plaque with the name of the Hotel and doorbell. They should come down to help you with your luggage.