The V should AFAIK roll slightly better than the IX, - it's all muscle powered and the aircraft is lighter.
The V had a very delicate C.o.G. by the way. While that had a very big effect on pitch, I am not sure on roll.
The IX would be more nose heavy.
With a flick-roll, the V would definately be swifter than the IX, however a Mk I would be even swifter while being unmoveable at speeds where the other ones could still roll...