I borrowed a friend's F55 for a day a while back. It wasn't my cup of tea as it is very light compared to my OM and I like my cameras to have a bit of weight, but it done the job. I don't have much expereince with autofocus but it seemed quick enough in daylight conditions. One thing I was less sure about was the controls in full manual mode, I found them less intuitive than the EOS300V I tried at the same time. I'm sure i'd have got used to it over time but, at the end of the day, I decided to stick with my Olympus for now.