Last year we rented a Suzuki XL7 SUV from American. While it was an older vehicle, it was fine and as Corinne said, it served its purpose. They offered the best price that we could find at the time, and the overall experience was satisfactory. We have a reservation with them again this Saturday for 10 days.
We have read very little (good or bad) about American, so we're giving them another try - a Yaris this year. We attempted to book Tropic 4 months in advance, but Hans was totally booked at that point.