Gates need to be sag-proof. The weight of a gate over time will cause it to sag and go out of square. Then it never closes properly, and you will be constantly shaving off the edges and adjusting the latches. If the inside frame is solidly built, it will never warp or sag. One way to build a good gate is to use a table saw with a Dado blade. As you can see in the Gate 2 picture, the corners are Dado blade cut, to the proper depth, and glued and screwed. These are even better than the metal corner kits sold in the lumber stores.