[Sawdust74]

What is the benefit of an insert vs a base plate mount?

 

[Gene Howe]

Depends on the insert and router attachment design. Mine's a Jessem and the router is clamped within the lift. It's far sturdier than a plate alone.
If you're not contemplating a lift and, have a smaller router, using the router plate would be fine. Probably be easier to change bits, too.

 

[reuelt]

What is the benefit of an insert vs a base plate mount?

Originally, the insert was proposed because routers have handles so it was wider that the baseplate (especially plunge routers) and so it was not possible to take out the router from the top to change bits if base plate mounted unless the baseplate is replaced with a larger diameter and thinker base plate.
The hole of the baseplate is large for bigger diameter bits to pass though. With a router table insert, it is possible to reduce or enlarge the hole with plastic sub-inserts depending on the bits used.