I finished my table this weekend and loaded up the egg. The wood is fir and the counter is concrete with some black coloring added.
Overall, I'm pretty happy with the result. I think if I were to change anything, I'd go with 4 or 5 inch caster wheels rather than 3 inch. I'm at about 50% of the caster weight capacity so they're fine, but I think it'd be easier to move with 4 or 5 inch wheels.
Of course, I still need to add a bottle opener, some type of handle, some hooks and maybe something to hold the plate setter below the countertop.