Just got it myself after seeing numerous good reviews. It actually works really well & correctly. It seems pretty good.

It's using Bungie's API. For those of you that don't know what that means, there's nothing this can do that the official Companion app can't. What it's doing is the exact same as the companion app except it's providing a much, much better interface for it. Noone has ever lost weapons or armour using the app, it's actually completely impossible to do so, because Bungie controls what data it can/can't use. For the same reason it's not possible to duplicate items, or delete them, as the API/Companion app doesn't let you. The programmer has this to say on the matter - [quote]“Let me just say that over the past five months, I’ve probably moved more gear through DIM than anyone else in the process of building this app. I have never lost an item. DIM can’t do anything that the Bungie.net website or the official companion app can’t do—most importantly dismantling items. There is currently no possible way to do that outside of the game itself.”[/quote] Even Bungie employees use it. [quote]We’ve heard from individuals that work at Bungie, and they tell us that they use DIM and really enjoy it.[/quote] So yeah. Don't use it if you don't want to, noone will make you! But it's much, much easier to use than any other gear management app available at the moment.