DEFINITELY worth owning both! Both are in my top 5 ... and different enough to warrant that. The more experienced noses around here will be able to describe the notes for you ... but to me, they're very different.
The problem may be that Eav des Bavx doesn't seem to be all that popular around here ... and Bois d'Argent is not something that all that many seem to own because it's fairly hard to get. So getting someone else's opinion who owns both may be tough.
For me personally, I don't see either coming off my top 5 list anytime soon. But they're not alike.