I flew Comair myself in J from Johannesburg to Victoria Falls just last week and found the service and flight in general to be excellent. (The lunch served was chilled and not large but it's a short hop so did the trick nicely.)
Additionally I had the chance to fly Airlink in Y and SA in J (this was somewhat on purpose to experience all three). All flights were surprisingly pleasant and on time. And definitely more enjoyable than the hassle I was given re: my US CDC vaccination card at Cape Town Int'l.