for my two cents worth .. both operators have a different core business.
Not all SA pilots start on the Bn2B .. which is the only type based on HID. It could depend if the requirement at the time of the job offer is for one of the other types and they may need someone already endorsed on that type, or if they need several Bn2B drivers at the same time.
I guess it would come down to whether you wanted to fly RPT or low level .. contracts with SA are longer than 12 months. I can only talk of SA experience wise, and can't say I've heard too many grumbles from any of the staff.