Actually, it seem that all of them are equally accurrate since all get the same database from the same registering-something authority. Paid one won't give you any additional accurracy then, as long as the free solutions are updated frequently (my was inaccurate because I haven't downloading updates since 2 years ago
). Actually free ones might be more accurate since you can download as often as you want while paid ones might charge per update which will make you update less frequent and the whole thing would be less accurate in the end.
