Their flights between Gatwick and Harare seem to be full most of the time. I've seen the queues at Gatwick on departure, and the other day I called them as needed to get a friend down to HRE and she wanted a single segment flight, and they were full between 25 MAR and 03 APR.
I'm told, some of you guys will know better, that although they are unreliable as Bob tends to take aircraft out for his own use, they are safe, probably for the same reason.