I followed the same basic dimensions as shown, but put mine up on casters. This allows me to move and angle the rack to get at material while storing tight to the wall under my wood storage. The only issue is the casters raised the rack significantly and blocked one of the outlets I had hoped not to. Oh well, a heavy duty extension cord solved that. The rack did show a tendency to tip with a piece of Melamine-covered MDF on it, but once loaded with other plywood it was fine.
The front railing was just the right height. It allowed me to raise a piece of plywood over it to set it on the rack while still being tall enough to keep pieces from falling over.
(Aside: Weather) Wow, jelly bean (the good ones, not those tiny poorly flavored jelly bellys) sized hail and it's dark at 5:00. It hasn't been getting fully dark until 6:30.