The table shows some banding across the top from the factory construction process. We decided to leave that in as a character element.
The poly adds a slightly yellowed tint that gives a warm feel. Water based poly does not have this effect.
The top is hollow in the center section underneath, an Ikea cost savings. The wood is full thickness for the three inches on either end.
I had some 3/4 plywood in the garage that I cut to the size of the hollow are area. Ie glued the plywood underneath the table and then screwed hairpin legs through the plywood into the top using 1 1/4" #10 screws. I drilled pilot holes using the "duct tape depth mark" trick so as not to go through the table top.