I can't speak to the table version but I just picked up the "old" version of the Summit & it has the gas ignition which quite frankly I didn't think I would care about but love now that I have it. The deflector is different in the old vs new, the old deflector is a two piece hinged design vs a new stamped steel offering. The wheels & casters are different on the old vs new, the frame on the old vs new E6 is also different with the older one being a little more sturdy compared to the new. I have also read a thread on here that indicates that the older versions only had two charcoal grid locations while the new offers a third location depending on the date of manufacturer. There is also the difference of the rapid fire vent on the top, there have been claims that the older design was better than the new one as far as quality of materials. Other than that I am not sure, my perspective on these grills is mainly on the old grill vs the new E6 so some if not all may not apply to the table version. Also the general thought was that the older units were more expensive so there have been some cost savings on the newer one's to get the retail price down, again take that with a grain of salt but there's my two pennies worth!
IIRC, the difference(s) were which market the grill is being sold in. USA/MX E6's have the two (2) mounting points for the coal grate. Personally, I don't see how one would need or use 3. Bottom most position is the dump spot for large coal loads to smoke on, the upper can be used with the provided baskets or coal banking to get dual zone and/or indirect/direct solutions, and you could use the upper for a large direct cook (think kebobs) along with veggies.