Also, if I remember right (from using the Reebok step for the first time last month at a gym), the Reebok step starts at 6" and the first riser bumps it up to 8". The Original Step has the 4" platform and you go up from there.
Like I said, I used the Reebok step for the first time at a gym last month and really had a hard time with the harder plastic, sharper edges, and less traction on top. I'd go with the Original!