I don't want to get too involved in the router table issues but one thing I have not seen mentioned is that when you have a router that comes out of the table (on a large mounting plate) this leaves a large hole in the table. When you are changing bits, template guides, setting bit profiles you need to have a place to sit the router. On the off-set table you have a place. On the centered ones...... well if it is a large centered one. So on this issue alone I would put a check on the off-set side of the list.