I spent some time Saturday morning while the kids were watching cartoons checking out the new Guild Vaults over on the PTR's. Because I wanted the GM perspective, I had to go around begging people to sign my guild roster. It wasn't too bad; people generally respond positively if you ask nicely (and if they're unguilded).
Once formed, I went straight to the bank. I happen to be in Iron Forge, so I know that the Vault is there on the same wall where you first enter the bank (near the mailbox, but inside). It cannot be accessed if you are not in a guild. You can purchase up to 6 tabs where you can place items. Each tab has the storage capability of 98 items. Each tab has an increased price tag: 1g, 10g, 100g, 1000g, 5000g, 10,000g. That's a potential of 588 spaces for only 16,111g. Ouch. Each tab has it's own log as to what happens to each item. And if you have the permissions, you can move items between tabs (that will be on the log as well). The Guild Master can assign which rank can see each tab and how many items/stacks they can take out per day.
The money is in one group (no individual tabs here), but has the control per rank of how much can be withdrawn per day. There is a log on the money as well. Now when you go to repair, you can repair individual items, repair all, or repair all from Guild Vault funds. The thing I really don't understand though is that if you repair your items using the Guild Vault funds, the money is "withdrawn", but nothing is logged. I suppose that's so substantial withdrawals aren't hidden in "silly" repair costs, but I'd like to see where that money goes. Accountants may lose their minds over this unbalance.
I didn't have enough money to buy the 5th and 6th slots, but 4 was sufficient for my testing needs. Everything seemed to work perfectly except for a small bug. The 4th tab would let me deposit items, but not withdraw. My new-found guildies found the same to be true. Hopefully the bug report I filed will take care of that. And we could still move the items from the 4th tab to another, so it's not like they were fully locked. Also, I gave all permissions to all tabs and I was the GM, so I had full control. Anyway...
Overall, I think it's a great idea. I really like that you can finally easily share items in a guild without violating the EULA by sharing an account. My biggest concern is with the money though. Especially with the non-logging of repairs, it seems to be a huge potential for getting taken advantage of. And how do you generate that money? Currently, when you run a raid, you take the proceeds and use those for repairs. If you haven't had a wipe fest, you've probably even come out ahead (or hopefully). But with how it currently stands, the guild vault will have this constant battle to not become bankrupt. It's almost as if there should be some automatic deposit, like an option where 50% of the money that drops goes to the guild Vault and the other 50% goes to the raid member's guild vault. Otherwise, that small amount each time may be overlooked or, like I said, taken advantage of.