I have never fished a Dobyns but here is what I see.
The D is 3 inches longer and has an extra fast action. I only build topwater or jerk bait rods with an extra fast action. I think that puts too much stress on the tip during the hook sets on a frog rod.
And without comparing the blanks side by side, I would say, just based on the list price on the Dobyins with Kigan Sic guides, the Rainshadow blank would be far superior to the blank Dobyns started with.