Warren in Lancaster, PA
In traditional work we use long tenons going into the legs. For legs that are 2 7/8 square the mortises would be about 2 1/2 inches deep and the tenons would be mitred at the ends to keep from overlapping. In fact the advantage of having heavy legs like this is so that we can make a more robust joint. This is the kind of joint that can easily last six or eight generations. This construction is much stronger than short tenons or dowels or even a whole box of screws. A corner brace does little for a first class joint.

I agree about using solid wood for the legs. Laminated legs inevitably open up and are unsightly and difficult to repair.