There's not much to say about Cyborg 009 vs Devilman. The story is sub-par, there is no character development as it assumes you already know the characters beforehand, and it's entirely gratuitous with its action sequences. This is what I imagine you get when two teams get stoned together and someone says "Wouldn't it be neat if we made a cross-over?"
If you're a fan of either of these franchises then you might enjoy this series to get more screen time with your favorite characters. If you're a fan of both franchises then this OVA series will be pure ecstasy for you. All in all it's a good time waster but definitely won't be topping any list