John, my router table--Bench Dog ProTop has an offset router. It is a bit closer to the front than the rear. I also have a Bench Dog fence on it. With the added space to the rear, I can push the fence back when I don't want it without having to remove it. Sometimes I will turn things around and work from the back when dealing with larger work pieces.
One thing I find a bit annoying with most factory made router tables as well as some home made ones is that the mitre gauge slot is too far from the router. Mine is on the front edge and it drives me nuts.
If I was making a router table now, I would do one of two things. I would either run a track for a miter gauge along the front edge of the router plate or mount the router directly to the underside of the table without a plate and run a couple of parallel tracks with one being about 3 1/2" from the center of the bit.
