The most useful upgrade in a Vredehoek flat is often not the lock at all — it is a closer with proper backcheck, which stops the wind driving the door through its own arc and hammering the frame. Fit that and the latch, hinges and keeper all last dramatically longer. It is a small piece of lock repair work that quietly removes the cause rather than repeatedly treating the symptom.
On the flat door itself, height above ground genuinely changes the sensible specification. A ground-floor or garden unit with a slope, service lane or fire stair behind it deserves real pick and drill resistance, and that is proper high security locks territory. Eight floors up, where the only approach is a monitored lobby and a lift, the money is better spent on a door that closes and latches reliably every single time.
For sectional title schemes there is a third option worth knowing about. Rather than every owner independently rekeying whenever a tenant leaves, a scheme can run a master key system where the building key and the unit keys sit in a designed hierarchy. Trustees keep controlled access to communal areas, owners keep exclusive access to their own units, and a single lost key stops being a building-wide problem.