A wonderful hotel, very nice and helpful staff. We had a room with a terrace, which added a significant dimension to the place. Rooms are clean, perhaps a bit small, but larger than I have had in London. The hotel even offers laptop loaners, which came in handy as we hunted for Halal restaurants. Not sure why some reviewers have said the location is "off the beaten track" or a bit far from stuff, because the Lilium's location is perfect. Easily walkable to either Termini station (with bags) or the Repubblica station. One day we WALKED from the hotel to the Spanish Steps and on down to Trevi and the Coliseum. Right around the hotel you can stumble on great food everywhere.
I take away one star from the overall because of one bizarre episode the morning of our departure. I left my bags in the lobby and ate a quick breakfast in the breakfast room adjoining the lobby. This was just after 7AM. After breakfast I find that my camera was taken from where it was laid on top of my bags. Nobody came thru the lobby that morning, mind you the hotel is behind a locked street door and 3 flights up. There is just NO foottraffic anywhere close. Only the croissant delivery guy came thru that morning, at exactly those minutes I was in the breakfast room. Clearly he boosted my camera. However the hotel staff refused to entertain that possibility. I was stupid to leave my stuff unattended perhaps. But you have to see this hotel to understand how secure I felt doing so. Ultimately I was not pleased with the lack of zeal on the part of the front desk staff to investigate. They just flat out said it was "impossible" that the bread dude took my camera.
I would recommend this excellent hotel, but just take care as if you are staying at the Hilton in Tenderloin - er - that is, Union Square, SF.