Exodar is actually kind of nice assuming you have a mount.

Mailbox right outside the AH and Bank which are close together, and anything you need is in a close radius.

But I couldn't defend Darnassuss' layout to save my life..

I'd rank the Exodar as equal to Ironforge, it's only disadvantage is its lack of convenient flight paths. Stormwind definately beats Ironforge these days aswell in my mind.

Darnassus is way worse than Exodar, though it might be quite nice if you could use flying mounts there.

The only problem I have with stormwind is that goldspam seems to be a nightmare there I'm my server. And if you go into the bank they actually run up to you and whisper adds.
I've had this happen and then had another 80 bank user whisper me to say he saw me trading with a farmer and they'd reported me.
Still I'm set in my ways and often forget there us an ah in any city but ironforge now. (showing age)

For my bank alt, it's Stormwind. But if my main needs to hit an AH really quick, it's all about Exodar. Assuming you arrive via Dalaran, you're still mounted and can easily get to the AH. Any other Alliance city you're dismounted as soon as you get there. It's surprising how much time it saves.

If you're starting to lvl jewelcrafting, Exodar can't be beat as it's the only place before you get to Outland that has an AH and a JC trainer. Once you out-level the trainer there then any other city will do just as well.

Darn has one nice advantage: For Druids without a hearth left, you can Moonglade your way there pretty quickly. Occasionally I run a rep run or two after hitting the instance, and note that I'm still waiting for my hearth when I'm ready to cash out.

It's a pain to hit bank-AH-bank again, but if you can keep it to one bank-AH run, you can drop guild contribs, grab mats from bank, grab balance of mats from AH, craft, and sell before logging off in your hometown.