Well, so far I have only used the Auctionhouse one time.
So far, not great.
It is actually quite clunky at this point, and unless they change some things before release, the lack of addons is going to make things extra rough.
You can search by specific item type and by strength level (rare etc.), but the sorting is not great. I had a hard time doing an individual search for items.
I was also annoyed that you could not sort the auctions you were searching by bid price or time left on the auction. Only by DPS (on weapons) and buyout amount.
Another odd thing is that it shows a bunch of expired auctions. I am not sure what the purpose of this is.
Anyways, the AH seems clunky.....it will not stop me from using it, but there it is.