Thanks for sharing your build, Bill. I need to build a dining table so your undercarriage treatment was of great interest to me. I really like that approach.
My top will be from some 8/4 Eastern White Pine (which I'll plane down and chamfer the edges on to decrease perceived bulk the Shakers did this a lot. It provided structural strength but gave the appearance of lightness.) and I haven't decided what hardwood to use for the undercarriage yet. All I have in the shop right now is some mahogany which seems like a bit too much contrast. I can get more large size pine but the scantlings would have to increase way beyond what I want so it'll need to be a hardwood.
My goal is more of a "farm table" than yours. If I had a more elegant place to put it, I'd definitely go with something closer to your design. As it is, I'd be putting a Rembrandt in an outhouse.
Doug