I still like my cutting grid, but then I have the open space where I normally park my motorcycle to set it up. Same as you though, I just slide the plywood off the back of the truck and right onto the grid - no lifting is involved.
The grid breaks down into 6 pieces - the two long ones and four cross pieces, I did make two strips that fasten to the top of my sawhorses that have dadoes cut across the width for the cross members - this stops the grid from sliding as you apply pressure when cutting.
I have used the grid as a worktop too, assembled the cabinet on top after cutting everything to size. And even set up the Kreg jig on the top and drilled all the pocket holes.
The nice thing about it is that it takes minimal space - when broken down, the parts store neatly on top of the little storage shelf unit that I build against the wall.