I've used OO twice and am completely satisfied with their performance. They get full marks for being precisely on time, for charging in 15 minute increments and not by the hour, for careful professional disassembly and reassembly of my furniture, and for being clean and neat. I've had nightmare experiences with other movers in this city and this was refreshingly good.
I'll add that I used them for two small jobs, most recently to flip two bedrooms, and both have massive, difficult to work with beds and heavy mattresses and the two movers were flying blind as I had not guide for them and both bed frames were very different, so successfully taking one apart and putting it back together in no way clarified how to manage the second. They figured out everything and were in and out of my home in 75 minutes.