I do not have a mortise machine. I keep looking at these, but have not yet taken the plunge.
When I have the need to make mortise and tenon joints I use the table saw to make the tenon. Steve linked a recent thread on using dado's to make the tenon.
I use my drill press to make the mortise using a brad point bit. I find these cut faster than a Forstner bit, especially if the mortise is deep.
I then clean up the mortise with a chisel. I do have a corner chisel which helps for the corners, but a normal chisel also works.
The router method works, but takes more setup time for the stop blocks, or the time to make a jig for a top bearing bit.