On Wednesday, September 9, 2015 at 9:04:33 AM UTC-5, wrote:
My plan is to either use biscuits or some kind of spline for greater strength and alignment. I'm not quite sure here so any input would be appreciated.

I vote you use loose tenons, i.e., practice your loose tenon technique. I did this on my trestle table: https://www.flickr.com/photos/438361...n/photostream/


I also plan to put boards across the bottom of the top, about every 2 feet or so. Probably overkill, but I do want this to last a long time.

Yeah, I think that's overkill, also. On my table, I place a board near each leg unit, only, not every two feet. My leg units are 83" apart. Rather than every 2' apart, I vote you practice installing a few dutchmans, even if only on scrap boards. https://www.flickr.com/photos/438361...posted-public/

Sonny