Since getting to Moria, I've not left. I think I got in around level 54 and now I'm 56. One big worry is about leveling too quickly and making all my remaining out of Moria quests go grey.
I walk questing in the Water Works and looking around. Man, it's huge. I wondered - can Moria really be an expansion of its own? Well, I suppose yes. Not as large as SoA, but getting from one location to another is pretty much equivalent to many cross territory SoA travels.
On top of that... man, thinking about it... it's in a MOUNTAIN! Most of that has to be carved or dug or dragged in from other carving and digging. No duh dwarves are grumpy!!
I don't recall the books really talking about how truly large this place is, but Turbine's designers sure did an amazing job building it... bravo. I take lots of screen shots, but on another computer and I'm too - I don't know - to remember to put them on the file server for later uploading somewhere... and frankly, the image inclusion process for this blogging tool stinks. Anyway... maybe next time.