Dragon Slayer Upgrade Stats

I have never had the privelage of using this weapon, mostly because I am not a fan of 2 handed weapons so I am not sure how well it performs. It is supposed to have a bonus vs dragons but is the bonus good enough to compete with better 2 handed or even 1 handed weapons? Upgraded it has an awesome critical chance, and versus those dragons you need all the damage you can get to counter their nasty regen rates.