Prior to the introduction of the shared AD bank I, and I'm sure others, used the ZADX to basically achieve the same end.
The new AD bank does help where "loose change" is concerned, allowing you to pool ALL the AD and not be left with 23 here or 40 there.
One advantage the old AD pooling system had over the new was that you could buy Zen far easier.
Now you have to check the Zen price, go back to your bank, withdraw that amount, and go back to the ZADX and buy your Zen.
How about, (since Zen is also acct bound) linking your shared AD acct to the ZADX thereby allowing you to bypass the rigmarole and allow you to trade straight from the pool?
Not a major issue granted, but it would add to the idea that the shared AD bank is meant to make things easier.