I finally got myself a SBBN015 quartz tuna and took some comparison shots of the tuna can and the Fieldmaster, SBDC011 that I bought last year.
Seiko SBDC001 and Orient CFD0C001B
The Orient 300m diver is often compared to the Seiko 200m SBDC001 (aka Sumo) because both watches have similar case diameter and are of similar style. The Orient has a list price of JPY150,000 in Japan while the Sumo is only JPY60,000 (both prices exclude tax).
For a real life divers, there is no comparison. The Orient 300m is a professional diver that is designed to handle saturation diving while the Sumo is only good for scuba diving.
For the rest of us, we compare their physical attributes to decide which one we prefer. If you are choosing between the Orient and Seiko, here is a quick comparison for your reference.