Overall good quality product for the price. 

Door installation method is not user friendly. Here is the trick. These pins are at right length, quarter turn on the cam lock to lock the pin, pull the pin out thru the hole, drop another cam lock. Lock both cam locks to secure the connection.

To manufacture, for the heavy door, you need inner bearing wheels to support the weight, the wheels will not last with ID turning against the bolt and OD turning against the rail. Dents on the wheels after couple open and close.