Dabura ~ the strongest incarnation of Cell we saw.
There's no asteriks or stipulations when Vegeta/Goku compare Dabura to Cell, that's fanon to make Cell seem more impressive.
It doesn't make any sense to specifically compare Dabura to any weaker version of Cell without clarification. His power is the topic so unless you add that asteriks, it's Super Perfect Cell.
Either way Dabura v. Cell goes 50/50 maybe 55/45 with full intel for Dabura. He has a good hard counter for regeneration.