They are quite similar in taste. Vuelta Abajo is a distinct variety in FTT hands, and modern growers in the Dominican Republic are careful to maintain the purity of their seed as well. But 90 to 100 years ago, Vuelta Abajo seed was a loose category that encompassed the careless collection of variants grown at that time in western Cuba. I assume that the "Vuelta Abajo" of today's Cibao Valley is not exactly the same variety as today's FTT (Jitterbugdude) Vuelta Abajo.
"But...does it taste Cuban?"
Well, yes and no. From a varietal standpoint, yes. There are distinctive, subtle aromas there. But the Cibao Valley Vuelta Abajo lacks the same intensity, and is smoother than Cuban leaf. (Yeah. I know. Some folks insist that Cuban leaf is the smoothest thing since peanut butter. But I haven't associated "smooth" with Cuban leaf in the nearly half century that I've sampled Cuban cigars.)
The Dominican Republic shares (with Haiti) the island of Hispañola, directly east of Cuba. You might expect similar growing conditions. But Florida, Jamaica, Honduras and the Yucatan of Mexico are all closer to the Vuelta Abajo than Hispañola.
I think the underlying question is whether or not the Cibao Valley Vuelta Abajo is really super special. Answer: no. It's really nice, though. And it is similar to my home-grown Vuelta Abajo (of Jitterbugdude lineage), only better aged, and way more consistent in quality.
Bob