After taking the expected St. Peter's tour and being overwhelmed by its size, we stopped off at this church on the way to the Colosseum. The church is tied closely to the Counter Reformation and St. Ignatius. We were not disappointed. The heavy baroque artwork and gilding were wonderful, but what struck me the most was the intimacy of each of the smaller side chapels and a sense of true reverence, with or without the glitz. We liked it so much that after we got back from the Colosseum, my husband went back with his camera to take picts, except for some inexplicable reason the church was closed. This was about 3:30, well before winter closing hours.
I highly recommend a visit to it. Everything is so very close in Rome. On the map the distances look daunting, but these are small blocks by U.S. standards.