I cannot say enough good things about Airlink having flown them a number of times from JNB to various safari destinations. No issues with my camera equipment. Booked through OTP since I wanted to keep my UA to JNB on one PNR, but single ticket J class was exhorbitant. But could get boarding passes from UA for the ex-JNB leg. On return, could only get Airlink boarding pass to JNB but once in the transit area could get UA boarding pass through the app. It only failed to work once so had to wait maybe an hour for a UA counter to open. Even checked bags a few times and made the connection in both directions.