level and heft
You might give some thought to the weight of the plate, lift (if any), and the router, too. Some systems are OK for smaller routers, but may be on the wimpy side for heavier rigs.
When I made a new top (two sheets of 3/4" phenolic BB ply, laminated with contact cement) for a BenchDog Pro lift and PC 7518 router, I used threaded brass inserts, one on either side of each corner, with machine screws and lock nuts on the bottom side of the table top. The inserts were drilled into the 3/8" wide rabbet that fits the cast plate of the lift.