Frequently, the tradeoffs seem pretty steep IMO. You save a bit of gold, but really, with what you give up, I question whether its a good trade. If you're losing 3 to all saves, taking a -2 to attacks and -4 to all skills, you need a +3 cloak, a +4 str item, and a ton of skill boosters to break even... did you save the price of those on your weapon that also required you to pay ritual costs and do side quests? Doubtful.
I particularly dislike any weapon that imposes an attack penalty, which just seems even more counterproductive. I changed it to where the penalty applies to other weapons, to signify your reliance on the legacy item.
I'm also curious why the designers seem to think the item gaining sentience is a bonus.
The book was a good concept, just executed in a mediocre fashion.