I stayed at Onomo for my first night in Libreville. The room was comfortable although a bit noisy when people are in the hallway. There also was no bottled water provided in the room, which I'd think would be standard for a hotel of this caliber. The hotel is located right across the street from the US Embassy, so is probably vert convenient for visiting bureaucrats. For others, however, it's a bit out of the way. I also heard that sometimes taxis are not allowed to come to Onomo because it's located near the presidential palace and they often close down to road. Fortunately I had private transport so didn't have to deal with this, but I can imagine that being a huge problem if not.