Yes, the smaller flat bed unit is much less "industrial like". Fwiw, I smear the nylon roller with high temp anti-seize, and lube the pusher all four sides with same. The nylon screws used as guides are a little mickey-mouse imo. The gap on the adjusted side allows fines will build up around the pusher, and cause binding. That said, I've had no issues with mine.
You can test for binding by adjusting the white screw all the way out. this allows moving the pusher in/out by hand to judge friction.
Back to topic, Here's a pic of the larger sloped bed, just down from top of page; http://keystoker.com/products.php
Mid way down, exploded view. Note four grates;http://keystoker.com/manuals/2012/A-250-A-350-A-450.pdf
I can't find a pic of the flat bed, but it really isn't all that much smaller. Stovepipemike used the term bunching up. That's my point. I wonder if a little down angle on the bed would allow the coal to push easier, and therefore be less densely packed on the bed = better burn.
I know, it ain't broke, but I fix things often, and then re-fix them back. LOL